The information in this preliminary prospectus supplement is not complete and may be changed. This preliminary prospectus supplement and the accompanying base prospectus are not an offer to sell these securities and are not soliciting an offer to buy these securities in any jurisdiction where the offer or sale is not permitted.

Mines Management, Inc. is offering 6,000,000 shares of its common stock. See the sections entitled "Summary," "The Offering" and "Underwriting" beginning on pages S-5, S-7 and S-28 of this prospectus supplement, respectively.

Our common stock is listed on the NYSE Amex LLC, or NYSE Amex, under the symbol "MGN," and on the Toronto Stock Exchange, or TSX, under the symbol "MGT." On November 9, 2009, the closing price for our common stock on the NYSE Amex was $2.70 per share and the closing price on the TSX was CDN$2.88 per share. The common stock will be offered publicly in the United States and on a private placement basis in other jurisdictions where such offer and sale is permitted.

For a description of our common stock, see "Description of Common Stock" on page S-27 of this prospectus supplement and page 17 of the accompanying base prospectus.

Investing in our common stock involves a high degree of risk. See "Risk Factors" beginning on page S-9 of this prospectus supplement, and the documents incorporated by reference herein or therein.

We have granted the underwriter a 30-day option to purchase from us, at a price equal to the public offering price, less the underwriting discount, up to an additional 900,000 shares of our common stock, to cover over-allotments, if any. See the section entitled "Underwriting" on page S-28 of this prospectus supplement.

The underwriter expects that the shares of common stock will be available for delivery in book-entry form through the facilities of The Depository Trust Company on or about November , 2009.

As of November 9, 2009, the aggregate market value of our outstanding common stock held by non-affiliates, or the public float, was approximately $54.8 million. We have not offered any securities pursuant to General Instruction I.B.6 of Form S-3 during the 12 calendar months prior to the date of this prospectus supplement.

Neither the Securities and Exchange Commission, or SEC, nor any state securities commission or other regulatory body has approved or disapproved these securities, or determined if this prospectus supplement or the accompanying base prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

You should rely only on the information contained or incorporated by reference in this prospectus supplement, the accompanying base prospectus and any free writing prospectus relating to this offering. We have not, and the underwriter has not, authorized any other person to provide you with different or additional information. You should not rely on any unauthorized information or representations. This prospectus supplement and the accompanying base prospectus are an offer to sell only the shares of common stock offered hereby, but only under circumstances and in jurisdictions where it is lawful to do so. The information contained in this prospectus supplement and the accompanying base prospectus, or the documents incorporated by reference herein or therein, is current only as of their respective dates, and our business, financial condition, results of operations and prospects may have changed since those dates. Information in this prospectus supplement updates and modifies the information in the accompanying base prospectus and information incorporated by reference therein. To the extent that any statement made in this prospectus supplement or any free writing prospectus differs from those in the accompanying base prospectus, the statements made in the accompanying base prospectus and the information incorporated by reference therein are deemed modified or superseded by the statements made by this prospectus supplement.

This prospectus supplement relates to a registration statement that we filed with the SEC utilizing a shelf registration process. Under this shelf registration process, we may, from time to time, offer, sell and issue any of the securities or any combination of the securities described in the accompanying base prospectus in one or more offerings. The accompanying base prospectus provides you with a general description of the securities we may offer. This prospectus supplement contains specific information about the terms of this offering of our common stock. This prospectus supplement may add, update or change information contained in the accompanying base prospectus. You should read both this prospectus supplement and the accompanying base prospectus, together with the information described under the sections of this prospectus supplement entitled "Where To Find Additional Information" and "Incorporation of Certain Information by Reference" and any additional information you may need to make your investment decision.

Prospective investors should be aware that the acquisition of the common stock described herein may have tax consequences in the United States. Such consequences for investors who are resident in, or citizens of, the United States may not be described fully in this prospectus supplement or the accompanying base prospectus. See "Material U.S. Federal Income Tax Considerations" in this prospectus supplement.

In this prospectus supplement, unless otherwise specified or the context otherwise dictates, the terms "Mines Management," "Company," "we," "us" and "our" refer to Mines Management, Inc. and our subsidiaries, unless it is clear that such terms refer only to Mines Management, Inc. Unless otherwise stated, currency amounts in this prospectus supplement are stated in United States dollars and references to "$" are to United States dollars. References to "CDN$" are to Canadian dollars.

The registration statement that contains the accompanying base prospectus (SEC File No. 333-162555) (including the exhibits filed with and the information incorporated by reference into the registration statement) contains additional important business and financial information about us and the common stock that is not presented or delivered with this prospectus supplement. That registration statement, including the exhibits filed with the registration statement and the information incorporated by reference into the registration statement, can be read at the SEC website or at the SEC office mentioned under the section of this prospectus supplement entitled "Where To Find Additional Information."

We file annual, quarterly and current reports, proxy statements and other information with the SEC. You may read and copy materials we have filed with the SEC at the SEC's public reference room located at 100 F Street, N.E., Washington, DC 20549. Please call the SEC at 1-800-SEC-0330 for further information on the operation of its Public Reference Rooms. Our SEC filings are also available to the public on the SEC's website at www.sec.gov. In addition, we maintain a website that contains information about us, including our SEC filings, at www.minesmanagement.com. The information contained on our website does not constitute a part of this prospectus supplement, the accompanying base prospectus or any other report or documents we file with or furnish to the SEC.

In addition, because we are traded on the Toronto Stock Exchange, we are subject to the filing requirements prescribed by the securities legislation of all Canadian provinces. These filings are available electronically from the Canadian System for Electronic Document Analysis and Retrieval at www.sedar.com, which is commonly known by the acronym "SEDAR."

This prospectus supplement, the accompanying base prospectus, any free writing prospectus and the information and any documents incorporated by reference herein and therein contain "forward-looking statements" within the meaning of the Private Securities Litigation Reform Act. All statements, other than statements of historical facts, included in this prospectus supplement, the accompanying base prospectus, any free writing prospectus and documents incorporated herein and therein by reference and filed with the SEC that address activities, events or developments that we expect or anticipate will or may occur in the future are forward-looking statements. These include, but are not limited to, such things as those listed below:

The words "estimate," "plan," "anticipate," "expect," "intend," "believe," "will," "may" and similar expressions are intended to identify forward-looking statements. These statements involve known and unknown risks, uncertainties, assumptions and other factors that may cause our actual results, performance or achievements to be materially different from any results, performance or achievements expressed or implied by such forward-looking statements. Factors that could cause or contribute to such differences include, but are not limited to:

For a more detailed discussion of such risks and other important factors that could cause actual results to differ materially from those in such forward-looking statements, please see the section entitled "Risk Factors" on page S-9 of this prospectus supplement and, to the extent applicable, the "Risk Factors" sections in our Annual Reports on Form 10-K and our Quarterly Reports on Form 10-Q as filed with the SEC. Although we have attempted to identify important factors that could cause actual results to differ materially from those described in forward-looking statements, there may be other factors that cause results not to be as anticipated, estimated or intended. There can be no assurance that these statements will prove to be accurate as actual results and future events could differ materially from those anticipated in the statements. Except as required by law, we assume no obligation to publicly update any forward-looking statements, whether as a result of new information, future events or otherwise. Investors should review our subsequent reports filed with the SEC on Forms 10-K, 10-Q and 8-K and any amendments thereto. We qualify all forward-looking statements by these cautionary statements.

The SEC allows us to "incorporate by reference" in this prospectus supplement and the accompanying base prospectus certain information we file with the SEC, which means that we can disclose important information in this prospectus supplement and the accompanying base prospectus by referring you to the document that contains the information. The information incorporated by reference is considered to be a part of this prospectus supplement and the accompanying base prospectus, and the information we file later with the SEC will automatically update and supersede the information filed earlier. We hereby incorporate by reference the documents listed below, which were previously filed with the SEC, and any filings made with the SEC under Sections 13(a), 13(c), 14 or 15(d) of the Securities Exchange Act of 1934, as amended, or the Exchange Act, after the initial filing of the registration statement that contains the accompanying base prospectus and until the offering of the securities covered thereby is completed or withdrawn; provided, however, that we are not incorporating by reference any additional documents or information furnished and not filed with the SEC.

You may obtain copies of any of these filings by contacting us at the address and telephone number indicated below or by contacting the SEC as described above. You may request a copy of these filings, and any exhibits we have specifically incorporated by reference as an exhibit to the registration statement of which this prospectus supplement forms a part, at no cost, by writing or telephoning to:

Mines Management, Inc.
905 W. Riverside Avenue, Suite 311
Spokane, Washington 99201
Attn: James H. Moore, Vice President and Chief Financial Officer
(509) 838-6050

Readers should rely only on the information provided or incorporated by reference in this prospectus supplement and the accompanying base prospectus. Readers should not assume that the information in this prospectus supplement, the accompanying base prospectus, or any free writing prospectus, is accurate as of any date other than the date on the front cover of the applicable document.

This summary highlights information contained elsewhere in this prospectus supplement and the accompanying base prospectus and the documents incorporated herein and therein by reference. It does not contain all the information that may be important to you. You should carefully read the entire prospectus supplement and the accompanying base prospectus, including our historical consolidated financial statements and the notes to those financial statements in our most recently filed Annual Report on Form 10-K, together with the additional information described in this prospectus supplement under the headings "Where To Find Additional Information" and "Incorporation of Certain Information by Reference." You should also carefully consider the matters discussed under "Risk Factors" in this prospectus supplement and in the documents incorporated herein and therein by reference.

Mines Management, Inc. is engaged in the business of acquiring and exploring, and if exploration is successful, developing mineral properties, primarily those containing silver and associated base and precious metals. Our principal mineral property interest is the Montanore Project, an advanced exploration stage silver-copper project located in northwestern Montana.

We acquired the Montanore Project in late 2002, together with the drill core and geologic, environmental, engineering and cost data developed by the previous owners. In May 2006, we acquired property that provided access to the 14,000 foot Libby adit. The Libby adit, when extended, will provide access to the Montanore deposit. Through this acquisition, we also received the State of Montana operating permit for the Montanore Project. In March 2008, we obtained authorization from the State of Montana to resume the exploration activities started by the previous owner. We submitted revisions to the operating permit that allowed us to reopen the Libby adit in 2006 and to proceed with dewatering and rehabilitation of the adit. Since 2003, we have spent approximately $14.1 million on evaluation and updating of data originating from previous owners, permitting activities, acquisition of equipment, construction of site infrastructure, and development and construction of a dewatering system. As currently planned, the advanced exploration and delineation drilling program includes the following:

The objectives of our advanced exploration and delineation drilling program are to:

Results of the drilling program, if successful, would provide data to assist in the completion of a bankable feasibility study and further optimization of the mine plan. The advanced exploration and delineation drilling program, through completion of a bankable feasibility study, is expected to cost an additional $30 million.

In order to advance the Montanore Project, we must obtain the requisite project approvals and permits from the U.S. Forest Service, or USFS, the State of Montana, and the Army Corps of Engineers. A draft environmental impact statement, or EIS, was issued by the USFS and the Montana Department of Environmental Quality, or DEQ, in the second quarter of 2009. The comment period

has expired, and the agencies are responding to issues presented in the course of preparation of the final environmental impact statement. If all issues are resolved satisfactorily, a record of decision approving our proposed plan of operations could be issued by the USFS sometime in the first half of 2010.

Please see "The Company" in this prospectus supplement for additional information about our activities.

Our principal executive offices are located at 905 W. Riverside Avenue, Suite 311, Spokane, Washington 99201, and our telephone number is (509) 838-6050.

The following is a brief summary of certain terms of this offering and is not intended to be complete. It does not contain all of the information that will be important to a holder of our common stock. For a more complete description of our common stock, see the sections entitled "Description of Common Stock" in this prospectus supplement and the accompanying base prospectus.


Issuer		Mines Management, Inc.
Shares of common stock offered		6,000,000 shares, plus up to 900,000 additional shares that we will issue and sell in the event the underwriter exercises its 30-day option to purchase additional shares to cover over-allotments, if any.(1)
Price to the public		$ per share.
Shares of common stock outstanding before this offering		22,920,076 shares.(2)
Shares of common stock outstanding after this offering		28,920,076 shares of common stock (29,820,076 shares of common stock if the underwriter exercises its over-allotment option to purchase additional shares of common stock in full).(1)(2)
Offering jurisdictions		The common stock will be offered publicly in the United States and on a private placement basis in other jurisdictions where such offer and sale is permitted.
Listing		Our common stock is listed for trading on the NYSE Amex, under the symbol "MGN," and the Toronto Stock Exchange, under the symbol "MGT."
Use of proceeds		The net proceeds to us from the sale of common stock offered hereby are expected to be approximately $ ($ if the underwriter exercises its over-allotment option to purchase additional shares of common stock in full) after deducting the underwriting discounts and our estimated offering expenses. The proceeds are intended to be used for (i) funding the advanced exploration and delineation drilling program for our Montanore Project, (ii) the possible acquisition and exploration of new precious metals projects, properties or companies, and (iii) general corporate expenses, as more fully described in the section entitled "Use of Proceeds" beginning on page S-25 of this prospectus supplement.
Risk factors		See the section entitled "Risk Factors" beginning on page S-9 of this prospectus supplement and, to the extent applicable, the "Risk Factors" sections of our Annual Report on Form 10-K and our Quarterly Reports on Form 10-Q as filed with the SEC for information you should consider before buying our common stock.

(1)

The total number of shares of common stock issued in this offering will be limited to such number that when multiplied by the price to the public is no greater than one-third of our public float. See "Risk Factors—Our ability to raise capital may be limited by applicable laws and regulations" on Page S-17 of this prospectus supplement.

(2)

Based on shares of common stock outstanding at September 30, 2009, and excludes:

•: 1,710,000 shares of common stock issuable upon the exercise of stock options outstanding prior to this offering under our equity incentive plans, at a weighted average exercise price of $1.39 per share;
•: 2,565,000 shares of common stock available for future grants under our equity incentive plans; and
•: 5,300,784 shares of common stock available upon the exercise of outstanding warrants at a weighted average exercise price of $5.13 per share.

To the extent that any options or warrants are exercised, new options are issued under our equity incentive plans, or we otherwise issue additional shares of common stock or securities convertible into common stock in the future, there will be further dilution to our investors.

An investment in our common stock involves a high degree of risk. You should consider the discussion of risk factors set forth below and in the documents incorporated herein by reference and in the accompanying base prospectus and the other information in this prospectus supplement before deciding to buy our common stock. These risk factors list some, but not all, of the risks and uncertainties that may have a material adverse effect on our business, our results of operations, financial condition, cash flows and the market price of our common stock. Additional risks and uncertainties not currently known to us or that we currently deem to be immaterial may also impair our business operations. If we are unable to prevent events that have a negative effect from occurring, then our business, and our results of operations, financial condition, cash flows and the market price of our common stock could be materially and adversely affected.

We have no recent history of producing silver or other metals. The development of our Montanore Project would require the construction and operation of mines, processing plants, and related infrastructure. As a result, we would be subject to all of the risks associated with establishing a new mining operation and business enterprise. We may never successfully establish mining operations, and any such operations may not achieve profitability.

We have a history of losses and we expect losses to continue for at least the next three years.

As an exploration company that has no production history, we have incurred losses since our inception and we expect to continue to incur additional losses for at least the next three years. As of September 30, 2009, we had an accumulated deficit of approximately $42.2 million. There can be no assurance that we will achieve or sustain profitability in the future.

We are currently in the exploration stage of mining and have no proven or probable reserves, as those terms are defined by the SEC, on any of our properties including the Montanore Project. The mineralized material identified to date in respect of the Montanore Project has not demonstrated economic viability and we cannot provide any assurance that mineral reserves with economic viability will be identified on that property.

In order to demonstrate the existence of proven or probable reserves under SEC guidelines, it would be necessary for us to advance the exploration of our Montanore Project by significant additional delineation drilling to demonstrate the existence of sufficient mineralized material with satisfactory continuity which would provide the basis for a feasibility study which would demonstrate with reasonable certainty that the mineralized material can be economically extracted and produced. We do not have sufficient data to support a feasibility study with regard to the Montanore Project, and in order to perform the drill work to support such feasibility study, we must obtain the necessary permits to continue our exploration efforts. It is possible that, even after we have obtained sufficient geologic data to support a feasibility study on the Montanore Project, such study will conclude that none of the identified mineral deposits can be economically and legally extracted or produced. If we cannot adequately confirm or discover any mineral reserves of precious metals on the Montanore property, we may not be able to generate any revenues.

Even if we discover mineral reserves on the Montanore property in the future that can be economically developed, the initial capital costs associated with development and production of any reserves found is such that we might not be profitable for a significant time after the initiation of any development or production. The commercial viability of a mineral deposit once discovered is dependent on a number of factors beyond our control, including particular attributes of the deposit such as size, grade and proximity to infrastructure, as well as metal prices. In addition, development of a project as

significant as Montanore will likely require significant debt financing, the terms of which could contribute to a delay of profitability.

The exploration of mineral properties is highly speculative in nature, involves substantial expenditures and is frequently non-productive.

Mineral exploration is highly speculative in nature and is frequently non-productive. Substantial expenditures are required to:

If we discover ore at the Montanore Project, we expect that it would be several additional years from the initial phases of exploration until production is possible. During this time, the economic feasibility of production could change. As a result of these uncertainties, there can be no assurance that our exploration programs will result in new proven and probable reserves in sufficient quantities to justify commercial operations at the Montanore Project.

We may require additional financing after completion of this offering to complete our exploratory drilling program at the Montanore Project, the availability of which cannot be assured.

We intend to use a portion of the net proceeds of this offering to fund our exploratory drilling program at our Montanore Project, the results of which, if the drilling program is successful, are expected to provide data to support completion of a bankable feasibility study and further optimization of our mine plan. We are an exploration stage mining company and currently do not have sufficient capital to fully develop and construct the Montanore Project. Prior to the offering, we have sufficient cash on hand to fund our drilling program, regulatory permitting, and general and administrative expenses for approximately two years. We believe the proceeds from this offering will enable us to complete the permitting and exploratory drilling program, and to prepare a bankable feasibility study. However, uncertainties surrounding the permitting and exploratory drilling programs and, in particular, the permitting process, could require the project to take longer and cause costs to increase. If additional funding were required, we cannot guarantee that we will be able to obtain any additional financing on commercially reasonable terms or at all, nor can we guarantee that we will be able to fund or complete a bankable feasibility study. We may require additional financing after completion of this offering for future exploration activities, including the preparation of a bankable feasibility study, or if we encounter unexpected costs or delays in our drilling program. Furthermore, our estimated capital costs and operating expenses may change with our actual experience as our mine plan is implemented. Even if a bankable feasibility study is completed, commodity prices, the then-current state of financial markets or other factors may make financing for the development of the Montanore Project unavailable. If we fail to obtain the necessary financing when needed, we may not be able to execute our mine plan and we may be forced to abandon exploration and development of the Montanore Project. If we cannot adequately finance our exploration of the Montanore property and its subsequent development, we will not be able to generate any revenues.

Even if our exploration efforts at Montanore are successful, we may not be able to raise the funds necessary to develop the Montanore Project.

environment. The failure to obtain financing would have a material adverse effect on our growth strategy and our results of operations and financial condition. There can be no assurance that we will commence production at Montanore or generate sufficient revenues to meet our obligations as they become due or obtain necessary financing on acceptable terms, if at all, and we may not be able to secure the financing necessary to begin or sustain production at the Montanore Project. In addition, should we incur significant losses in future periods, we may be unable to continue as a going concern, and we may not be able to realize our assets and settle our liabilities in the normal course of business.

We may not be able to obtain permits required for development of the Montanore Project.

In the ordinary course of business, mining companies are required to seek governmental permits for expansion of existing operations or for the commencement of new operations. We will be required to obtain numerous permits for our Montanore Project. Obtaining the necessary governmental permits is a complex and time-consuming process involving numerous jurisdictions and often involving public hearings and costly undertakings. Obtaining required permits for the Montanore Project may be more difficult due to its location within the Cabinet Wilderness Area and its proximity to core habitat of certain protected species, including the grizzly bear, bull trout and lynx. In addition, a third party is seeking to permit another mining operation near the Montanore Project and, if that effort were successful, the impact of that operation on the environment and on wildlife in the area would have to be taken into consideration in our permitting determinations, and could make these determinations more difficult. Private groups dedicated to protection of the environment have been active in opposing permitting of other projects in and near the Cabinet Wilderness Area.

In addition, mining projects require the evaluation of environmental impacts for air, water, vegetation, wildlife, cultural, historical, geological, geotechnical, geochemical, soil and socioeconomic conditions. An EIS is required before we could commence mine development or mining activities. Baseline environmental conditions are the basis on which direct and indirect impacts of the Montanore Project are evaluated and based on which potential mitigation measures would be proposed. If the Montanore Project were found to significantly adversely impact the baseline conditions, we could incur significant additional costs to avoid or mitigate the adverse impact, and delays in the Montanore Project could result.

Permits would also be required for, among other things, storm-water discharge; air quality; wetland disturbance; dam safety (for water storage and/or tailing storage); septic and sewage; and water rights appropriation. In addition, compliance must be demonstrated with the Endangered Species Act and the National Historical Preservation Act.

The duration and success of our efforts to re-permit are contingent upon many variables not within our control. There can be no assurance that we will obtain all necessary permits and, if obtained, that the permitting costs involved will not exceed those that had been previously estimated. It is possible that the costs and delays associated with the compliance with such standards and regulations could become such that we would not proceed with the further exploration, development or operation of a mine or mines at the Montanore Project.

Operation of a mine at the Montanore site will depend on our ability to recruit and retain qualified employees.

If our exploration efforts at Montanore are successful and we are able to raise the necessary external financing to develop and construct Montanore Project, our ability to conduct mining operations will depend in part upon our ability to attract, compensate and retain a sufficient number of qualified employees, including executive officers, managers, employees and other personnel knowledgeable about the mining business. Qualified individuals of the requisite caliber and number needed to fill these positions may be in short supply in areas near the Montanore Project, and the challenges in attracting and relocating qualified employees to the Montanore site may be considerable. If we are unable to hire and retain employees to operate our mine, any planned commencement of mining operations in the future would be delayed. Furthermore, increases in labor costs due to the competition for qualified employees and hiring employees represented by labor unions could render mining operations at Montanore uneconomical. Any such delays or any increases in labor costs could have a material adverse effect on our business and financial condition.

Our future mining operations, if any, would be subject to all of the hazards and risks normally incident to developing and operating mining properties. These risks include:

Our future profitability will be affected by changes in the prices of metals.

If we establish reserves, complete a favorable feasibility study for the Montanore Project, and complete development of a mine, our profitability and long-term viability will depend, in large part, on the market price of silver and copper. The market prices for these metals are volatile and are affected by numerous factors beyond our control, including:

on the website www.kitco.com, during the five-year period ended September 30, 2009, the high and low settlement prices for silver were $20.92 and $6.39 per ounce. As reported on the website www.tradeservice.com, the high and low settlement prices for copper were $4.07 and $1.24 per pound during the five-year period ended September 30, 2009.

We have ongoing reclamation obligations on the Montanore Project properties.

Although we have posted bonds with the State of Montana to cover expected future mine reclamation costs, there is no guarantee that the amount of these bonds will satisfy the environmental regulations and requirements. Should government regulators determine that additional reclamation work is required, we may be required to fund this work, which could have a material adverse effect on our financial position.

Our operations and exploration and development activities are subject to extensive federal, state, and local laws and regulations governing various matters, including:

Failure to comply with applicable laws and regulations may result in civil or criminal fines or penalties or enforcement actions, including orders issued by regulatory or judicial authorities enjoining or curtailing operations or requiring corrective measures, installation of additional equipment or remedial actions, any of which could result in us incurring significant expenditures. We may also be required to compensate private parties suffering loss or damage by reason of a breach of such laws, regulations or permitting requirements. It is also possible that future laws and regulations, or a more stringent enforcement of current laws and regulations by governmental authorities, could cause additional expense, capital expenditures, restrictions on or suspensions of any future operations and delays in the exploration of our properties.

Changes in mining or environmental laws could increase costs and impair our ability to develop our properties.

From time to time the U.S. Congress may consider revisions in its mining and environmental laws. It remains unclear to what extent new legislation may affect existing mining claims or operations. The effect of any such revisions on our operations cannot be determined conclusively until such revision is enacted; however, such legislation could materially increase costs on properties located on federal lands, such as ours, and such revision could also impair our ability to develop the Montanore Project and to explore and develop other mineral projects.

pollution or other hazards as a result of the disposal of waste products occurring from exploration and production) is not generally available to us (or to other companies in the minerals industry) at a reasonable price. To the extent that we become subject to environmental liabilities, the satisfaction of those liabilities would reduce funds otherwise available to us and could have a material adverse effect on us. Laws and regulations intended to ensure the protection of the environment are constantly changing, and are generally becoming more restrictive.

Although the Montanore deposit is held by patented mining claims, a significant portion of our holdings consist of unpatented lode and millsite claims. Certain of our United States mineral and surface use rights consist of "unpatented" mining and millsite claims created and maintained in accordance with the U.S. General Mining Law of 1872, which we refer to in this prospectus supplement as the General Mining Law. Unpatented mining and millsite claims are unique U.S. property interests, and are generally considered to be subject to greater title risk than other real property interests because the validity of unpatented mining and millsite claims is often uncertain. This uncertainty arises, in part, out of the complex federal and state laws and regulations that supplement the General Mining Law. Also, unpatented mining and millsite claims and related rights, including rights to use the surface, are subject to possible challenges by third parties or contests by the federal government. The validity of an unpatented mining or millsite claim, in terms of both its location and its maintenance, is dependent on strict compliance with a complex body of federal and state statutory and decisional law. In addition, there are few public records that definitively control the issues of validity and ownership of unpatented mining and millsite claims. We have not filed a patent application for any of our unpatented mining and millsite claims that are located on federal public lands in the United States and, under possible future legislation to change the General Mining Law, patents may be difficult to obtain.

Our ability to conduct exploration, development, mining and related activities may also be impacted by administrative actions taken by federal agencies. With respect to unpatented millsites, for example, the ability to use millsites and their validity has been subject to greater uncertainty since 1997. In November of 1997, the Secretary of the Interior (appointed by President Clinton) approved a Solicitor's Opinion which concluded that the General Mining Law imposed a limitation that only a single five-acre millsite may be claimed or used in connection with each associated and valid unpatented or patented lode mining claim. Subsequently, however, on October 7, 2003, the new Secretary of the Interior (appointed by President Bush) approved an Opinion by the Deputy Solicitor which concluded that the Mining Laws do not impose a limitation that only a single five-acre millsite may be claimed in connection with each associated unpatented or patented lode mining claim. Current federal regulations do not include the millsite limitation. There can be no assurance that the Department of the Interior will not seek to re-impose the millsite limitation at some point in the future.

In addition, a consortium of environmental groups recently filed a lawsuit in the United District Court for the District of Columbia against the Department of the Interior, the Department of Agriculture, the Bureau of Land Management, or BLM, and the USFS, asking the court to order the BLM and USFS to adopt the five-acre millsite limitation. That lawsuit also asks the court to order the BLM and the USFS to require mining claimants to pay fair market value for their use of the surface of federal lands where those claimants have not demonstrated the validity of their unpatented mining claims and millsites. If the plaintiffs in that lawsuit were to prevail, that could have an adverse impact on our ability to use our unpatented millsites for facilities ancillary to our mining activities, and could significantly increase the cost of using federal lands at the Montanore Project for such ancillary facilities.

In recent years, the U.S. Congress has considered a number of proposed amendments to the General Mining Law, as well as legislation that would make comprehensive changes to the law.

Although no such legislation has been adopted to date, there can be no assurance that such legislation will not be adopted in the future. If adopted, such legislation could, among other things, (i) adopt the millsite limitation discussed above, (ii) impose time limits on the effectiveness of plans of operation that may not coincide with mine life, (iii) impose more stringent environmental compliance and reclamation requirements, (iv) establish a mechanism that would allow states, localities and Native American tribes to petition for the withdrawal of identified tracts of federal land from the operation of the General Mining Law, (v) allow for administrative determinations that mining would not be allowed in situations where undue degradation of the federal lands in question could not be prevented, and (vi) impose royalties on silver and copper production from unpatented mining and millsite claims located on federal lands or impose fees on production from patented mining and millsite claims. Further, it could have an adverse impact on earnings from our operations, could reduce estimates of any reserves we may establish and could curtail our future exploration and development activity on federal lands or patented claims.

While we have no reason to believe that title to any of our properties is in doubt, title to mining properties is subject to potential claims by third parties claiming an interest in them.

We are obligated by a right of first refusal agreement relating to our future silver production that may affect the willingness of third parties to enter into silver purchase agreements with us.

In November 2007, we entered into a Right of First Refusal agreement with a significant stockholder that granted to that stockholder a 20-year right of first proposal and a right to match third- party proposals to purchase all or any portion of silver mined, produced or recovered by us in the State of Montana. The right does not apply to trade sales and spot sales in the ordinary course of business or forward sales, in each case, for which we receive no upfront payment. The existence of this agreement may make other potential buyers for silver we produce less likely to negotiate with us to purchase silver, since they would be subject to losing the silver bargained for. A reduction in the number of bidders for our silver could reduce the price we can obtain for silver we produce.

The market price of our common stock is subject to volatility and could decline significantly.

Our common stock is listed on the NYSE Amex and the TSX. Securities of small-cap companies such as ours have experienced substantial volatility in the past, often based on factors unrelated to the financial performance or prospects of the companies involved. These factors include macroeconomic developments in North America and globally and market perceptions of the attractiveness of particular industries. This volatility has been exacerbated in the latter half of 2008 and the first half of 2009 because of global economic disruptions. Our share price is also likely to be significantly affected by short-term changes in silver and copper prices or in our financial condition or results of operations as reflected in our quarterly earnings reports. Over the last three years, the closing price of our common shares as reported on the NYSE Amex has fluctuated from a low of $0.57 per share to a high of $6.44 per share. Other factors unrelated to our performance that could have an effect on the price of our common stock include the following:

As a result of any of these factors, the market price of our common stock at any given point in time might not accurately reflect our long-term value. Securities class action litigation often has been brought against companies following periods of volatility in the market price of their securities. We could in the future be the target of similar litigation. Securities litigation could result in substantial costs and damages and divert management's attention and resources.

The issuance of additional common stock may negatively impact the trading price of our common stock.

We have issued equity securities in the past, will issue equity securities in this offering and may continue to issue equity securities to finance our activities in the future, including to finance future acquisitions, or as consideration for acquisitions of businesses or assets. In addition, outstanding options and warrants to purchase our common stock may be exercised, resulting in the issuance of additional shares of common stock. The issuance by us of additional shares of common stock, including the shares of common stock issued by us in the offering, would result in dilution to our stockholders, and even the perception that such an issuance may occur could have a negative impact on the trading price of our common stock.

Our management could have broad discretion over the use of some of the net proceeds from this offering, and you will not necessarily know how such proceeds are to be used. You may not agree with how we use the proceeds and such proceeds from this offering generally may not be invested successfully.

As described under the section entitled "Use of Proceeds" on page S-25 of this prospectus supplement, we may use some of the net proceeds from this offering for general corporate purposes, including, among other things, the funding of potential acquisitions. Therefore, particularly with respect to the portion of proceeds allocated to acquisitions and general corporate purposes, our management will have broad discretion as to the use of the offering proceeds. Accordingly, you will be relying on the judgment of our management with regard to the use of some of these net proceeds, and you may not have the opportunity to approve any particular acquisition or to assess whether such proceeds are being used in a manner of which you approve. It is possible that the proceeds from this offering will be invested in ways that do not yield a favorable, or any, return for us.

Our stockholders are subject to future dilution by the exercise of options and warrants, and the existence of a significant number of options and warrants and our policies related to repricing of stock options, could depress the price of our common stock.

As of September 30, 2009, we had 22,920,076 shares outstanding. As of that date, there were (i) options outstanding to purchase up to 1,710,000 shares of common stock at exercise prices ranging from $0.99 to $5.70 per share and (ii) warrants outstanding to purchase 5,300,784 shares at exercise prices ranging from $4.00 to $5.75 per share. 2,565,000 additional shares of common stock are available for issuance under our stock option plans. We have customarily repriced stock options when the exercise price falls $1.00 or more below the prevailing market price of our common stock. If we issue additional options or warrants, reprice our stock options, or if currently outstanding options or warrants to purchase our common stock are exercised, the investments of our shareholders would be further diluted. As a result of our repricing policy, officers and directors are not subject to the same risk as other stockholders in the event of a decrease in the stock price. In addition, the potential for exercise of a significant number of options and warrants can have a depressive effect on the market price for our common stock.

The exercise price of some of our outstanding warrants may be reduced by this offering.

We have outstanding warrants to purchase 1,882,484 shares of common stock that contain "full ratchet" antidilutions provisions, meaning that if common stock is issued at a price lower than the exercise price of the warrants, the exercise price of the warrants is reduced to the issue price of the common stock so issued. The exercise price of the warrants is currently $4.00 per share. Accordingly, if the purchase price of the common stock in this offering is less than $4.00 per share, the exercise price would be reduced to that price and the investments of our stockholders could be diluted if such warrants are exercised.

We have never paid cash dividends and any future decision as to the payment of cash dividends will be at the discretion of our board of directors and will depend upon our earnings, financial position, capital requirements, plans for expansion and such other factors as our board of directors deems relevant. We intend to retain our earnings, if any, to finance the growth and development of our business. Any return on an investment in our common stock will come from the appreciation, if any, in the value of our common stock.

Anti-takeover provisions in our articles of incorporation, our bylaws and under Idaho law may enable our incumbent management to retain control of us and discourage or prevent a change of control that may be beneficial to our stockholders.

Certain provisions of our articles of incorporation, as amended, our bylaws, as amended, and of Idaho law could discourage, delay or prevent a merger, acquisition, or other change of control that stockholders may consider favorable, including transactions in which you might otherwise receive a premium for your shares of common stock of our company. Specifically, our articles of incorporation divides our board of directors into three classes having staggered terms of office. This may prevent or frustrate attempts by our stockholders to replace or remove our management. We have also implemented a stockholders rights plan, also called a poison pill, which would substantially reduce or eliminate the expected economic benefit to an acquirer from acquiring us in a manner or on terms not approved by our board of directors. These and other impediments to a third party acquisition or change of control could limit the price investors are willing to pay in the future for shares of our common stock. Our board of directors has also approved employment agreements with certain of our executive officers that include change of control provisions that provide severance benefits in the event that their employment terminates involuntarily without cause or for good reason within twelve months after a change of control of us. These agreements could affect the consummation of and the terms of a third party acquisition. We are also subject to provisions of Idaho law that could have the effect of delaying, deferring or preventing a change in control of our company. One of these provisions prevents us from engaging in a business combination with any interested stockholder for a period of three years from the date the person becomes an interested stockholder, unless specified conditions are satisfied.

Our ability to raise capital may be limited by applicable laws and regulations.

Although we have an effective "shelf" registration statement on Form S-3 that allows us to raise up to $65 million from the public sale of common stock, preferred stock, debt securities, warrants, rights and units, we may not be able to use that registration statement to raise additional capital. Under current SEC regulations, at any time during which the aggregate market value of our common stock held by non-affiliates, or public float, is less than $75 million (calculated as set forth in Form S-3 and SEC rules and regulations), the amount we can raise through primary public offerings of our securities in any twelve-month period using a registration statement on Form S-3 will be limited to one-third of our public float. As of November 9, 2009, our public float was approximately 18,627,133 shares. Based on a market price of $2.94 per share, which was the average of the bid and asked prices

of our common stock on the NYSE Amex on October 8, 2009, the aggregate market value of our public float was approximately $54.8 million. The value of one-third of that public float was approximately $18.2 million; however, unless our public float exceeds $75 million in the future, the market price of all the common stock sold by us under this prospectus supplement will be subtracted from that amount to determine any future amount we can raise publicly using our Form S-3 shelf registration statement. Alternative means of raising capital through sales of our securities, including through the use of a "long form" Form S-1 registration statement or in private placements of equity or debt securities, may be more costly and time-consuming and more difficult to market to potential investors.

We may, in the future, engage in targeted acquisitions. Any acquisition that we make may change our business and operations, and may expose us to new geographic, political, operating, financial, governmental, environmental and geological risks. Our success in acquisition activities depends on our ability to identify suitable acquisition candidates, negotiate acceptable terms for any such acquisition and successfully integrate the acquired operations. Any acquisition would be accompanied by risks. We may expend considerable resources on pursuing an acquisition candidate, including on due diligence and negotiations, and we may ultimately not prove successful in completing the acquisition. Even if successful in completing the acquisition, the acquisition may present problems. For example, there may be significant decreases in commodity prices after we have committed to complete the transaction and have established the purchase price or exchange ratio; a material ore body may prove to be below expectations; we may have difficulty integrating and assimilating the operations and personnel of any acquired companies, realizing anticipated synergies and maximizing the financial and strategic position of the combined enterprise and maintaining uniform standards, policies and controls across the organization; the integration of the acquired business or assets may disrupt our ongoing business and our relationships with employees, customers, suppliers and contractors; and the acquired business or assets may have unknown liabilities which may be significant. If we choose to use equity securities as consideration for such an acquisition, our existing stockholders may suffer substantial dilution. Alternatively, we may choose to finance any such acquisition with existing resources which could materially affect our liquidity. There can be no assurance that we would be successful in overcoming these risks or any other problems encountered in connection with any acquisition.

There are differences in U.S. and Canadian requirements for reporting of resources and mineralization, and some information required by Canadian reporting is not permitted under SEC guidelines.

The mineralization figures presented in the documents incorporated by reference in this prospectus and our press releases and other public statements that may be made from time-to-time are based upon estimates made by independent geologists. U.S. reporting requirements for disclosure of mineral properties are governed by SEC Industry Guide 7. Although we are a U.S. company traded on the NYSE Amex, we also report estimates of resources that are prepared in accordance with Canadian standards because we are also traded on the Toronto Stock Exchange and are thus subject to Canadian reporting requirements. These resource estimates were prepared in accordance with standards of the Canadian Institute of Mining, Metallurgy and Petroleum referred to in Canadian National Instrument 43-101, commonly known as NI 43-101. The reporting standards required by NI 43-101 are different from the standards generally permitted to report reserve and resource estimates in reports and other materials filed with the SEC. Accordingly, information concerning descriptions of mineralization and resources contained in our public filings may not be comparable to information made public by other U.S. companies subject to only the U.S. reporting and disclosure requirements of the SEC.

Under NI 43-101, we report measured, indicated and inferred resources, measurements which are generally not permitted in filings made with the SEC. Under SEC rules, mineralization may not be classified as a "reserve" unless the determination has been made that the mineralization could be economically and legally produced or extracted at the time the reserve determination is made. U.S. investors are cautioned not to assume that all or any part of measured or indicated resources will ever be converted into reserves. Further, "inferred resources" have a great amount of uncertainty as to their existence and as to whether they can be mined legally or economically. In accordance with Canadian rules, estimates of inferred mineral resources cannot form the basis of a feasibility study or other economic evaluations. It cannot be assumed that all or any part of measured mineral resources, indicated mineral resources, or inferred mineral resource will ever be upgraded to a higher category. See "Cautionary Note to United States Investors Concerning Estimates of Measured, Indicated and Inferred Resources" on page 2 of the accompanying base prospectus.

Non-U.S. Holders who own, or in certain cases have owned, directly or constructively, more than 5% of our common stock will generally be subject to U.S. federal income tax on gain realized on the disposition of such stock.

Because we have significant U.S. real estate holdings, we believe we are a "United States real property holding corporation" (USRPHC) for U.S. federal income tax purposes. As a result, a "non-U.S. holder" (as defined in "Material U.S. Federal Income Tax Considerations—Non-U.S. Holders") will generally be subject to U.S. federal income tax on gain realized on a sale or other disposition of our common stock if such non-U.S. holder has owned, actually or constructively, more than 5% of our common stock at any time during the shorter of (a) the five-year period ending on the date of disposition and (b) the non-U.S. holder's holding period in such stock. Non-U.S. holders who may own, or may have owned, directly or constructively, more than 5% of our common stock should consult their own U.S. income tax advisors concerning the consequences of disposing of such stock.

Mines Management, Inc. is engaged in the business of acquiring and exploring, and if exploration is successful, developing mineral properties, primarily those containing silver and associated base and precious metals. Mines Management, Inc. was incorporated under the laws of the State of Idaho on February 20, 1947. Our principal executive offices are located at 905 W. Riverside, Suite 311, Spokane, Washington 99201, and the telephone number at that office is (509) 838-6050. Our Internet address is www.minesmangement.com. Information contained on our website is not a part of this prospectus supplement or the accompanying base prospectus or the documents incorporated herein or therein by reference.

Our principal mineral property interest is the Montanore Project, an advanced exploration stage silver-copper project located in northwestern Montana. We are in the process of re-permitting of the Montanore Project, upon completion of which we will continue with our advanced exploration and delineation drilling program. The results of this program will determine the feasibility for development of the Montanore Project. None of our properties is currently in production.

The estimate of mineralized material set forth below was prepared by Mine Development Associates, Inc., or MDA, in 2005. The estimate was prepared in accordance with SEC Industry Guide 7.

The Montanore Project was owned by Noranda Minerals Corporation, or Noranda, between 1988 and 2002. During that time, the project received a record of decision approving a plan of operations from the USFS and the State of Montana, as well as all other permits required for the project, allowing Noranda to proceed with full operations, but the project was never put into operation. From 1988 to 2002, we held royalty rights to a portion of the deposit. In 2002, Noranda announced that it was abandoning the project, and subsequently transferred to us by quitclaim deed the patented and unpatented mining claims that control the mineral rights, and all drill core and intellectual property, including geologic, environmental and engineering studies, relating to the Montanore Project.

In May 2006, we acquired two Noranda subsidiaries that held title to the Montanore property, providing access to the 14,000 foot Libby adit which, when extended, will provide access to the Montanore deposit. Through this acquisition, we also received the Hard Rock Operating Permit 150 that covers certain exploration activities and the Montana Pollution Discharge Elimination System water discharge permit for the Montanore Project. The 14,000 foot Libby adit was constructed in the early 1990s by previous operators. The adit stops approximately 2,000 feet short of the deposit. Prior to our activity in 2006, there were no plant, equipment, subsurface improvements or equipment other than the Libby adit, which was plugged and in reclamation. During the third quarter of 2006, we reopened the adit and completed initial water testing to determine the treatment method for water discharged from the adit. The necessary permit revisions were received in November 2006 to undertake a planned

$40 million underground evaluation drilling program. We own water rights associated with the Montanore property that we believe will be sufficient for proposed mining activities.

The stages of the advanced exploration and delineation drilling program, and activities undertaken to date in each stage, are set out below:

With the exception of the first 600 feet, the length of the Libby adit contains water. During this stage of the evaluation drilling program, we have developed a plan to dewater the adit and to treat the discharged water using ultra-filtration and possibly chemical pre-treatment so that discharged water, both during the dewatering process as well as during development of the adit and drilling program, meets Montana water quality standards. In 2007, we completed the design, procurement, engineering construction, start-up and pilot scale tests of the $1.3 million water treatment plant. In 2008, we continued to install and test the underground water pumping stations and sumps, and in early 2009 we proceeded with dewatering. We have retained an independent contractor, Small Mine Development, LLC, to manage the adit advancement and the drilling program. It has completed engineering for a new nitrate removal addition to the water treatment facility and installation of the initial sumps and pumping system. Two additional sumps and a decanting system were placed into service at the 7,200 foot level during the second quarter of 2009. These sumps are part of the overall dewatering system designed to clarify water from the adit before sending it to the water treatment plant on the surface. Construction of the nitrate system is scheduled to start when timing of the receipt of permits is more certain, and to be completed prior to beginning the final section of the adit to reach the ore body and install drill stations. The current schedule is to begin construction of the concrete chambers in late April/early May of 2010 based on timing of receipt of the record of decision following completion of a final EIS. Current operations on the Libby adit include continued operations on the Montanore site water treatment system and dewatering of the decline.

Concurrent with dewatering, we are rehabilitating the adit, which involves, among other activities, scaling the walls, installing new roof bolts and extending electricity, ventilation and dewatering infrastructure into the adit. Power for the planned evaluation drilling program will be provided by three on-site Cummins 800 KW generators. In the fourth quarter of 2006, we purchased a site generator and erected a warehouse building at the Libby adit site, along with an office and employee change facility. In 2007, an initial order of electrical supplies, ventilation material, pumping equipment, and ground control roof bolts and supplies was delivered to the site. Construction of a dry storage structure for inventory was completed in the fall of 2007. The initial fleet of surface equipment and underground equipment was purchased at a cost in excess of $6 million and delivered in the third and fourth quarters of 2007. During 2008, we added six additional staff and purchased additional equipment. Construction of the sumps has allowed us to test most of the mining equipment that will be used during the adit advancement and future development activities. To date, infrastructure placed in the decline includes a refuge chamber, mine power center and temporary pump station, along with the previously installed sumps and pumping system at the 700 ft. location. On April 30, 2009, Small Mine Development was demobilized, and the decline is now in a standby mode, until the environmental

review process progresses. Total costs for Stage 1 activities are approximately $7.3 million, of which approximately $2.5 million had been spent by September 30, 2009.

Once rehabilitation is complete and the permitting process is complete, we plan to advance the adit approximately 3,000 feet towards the middle of the deposit. Following the advancement of the adit, we expect to commence 10,000 feet of development drifting, which will be necessary to provide drill access. Once drifting is underway we will also begin to establish drill stations. The process of drifting and the establishment of drill stations will continue throughout the remainder of the program. We expect that Stage 2 will cost approximately $7.5 million.

In Stage 3 of the advanced exploration and delineation drilling program, we expect to commence approximately 20,000 feet of delineation diamond core drilling of approximately 50 holes totaling approximately 45,000 feet. We expect to spend approximately $0.5 million on Phase I delineation drilling. We also expect to spend approximately $12.7 million during Stages 1, 2 and 3 on site operating and capital costs, optimization studies and general corporate support. The Company has spent $3.7 million as of September 30, 2009 on site operating and capital costs, optimization studies and general corporate support.

During this stage, we anticipate completing an additional 25,000 feet of diamond core drilling, undertaking additional metallurgical and geotechnical testing and analysis, and if the results of our exploration are successful, preparing for and completing a bankable feasibility study at an estimated cost, with site operating and capital costs, of approximately $10.0 million.

We are currently doing trade off studies, reviewing the geology, and performing initial engineering reviews to improve our estimates of the projected costs and schedule for the final three stages of the program.

In order to advance the Montanore Project past the exploration stage, we must obtain the requisite project approvals and permits from the USFS, the State of Montana, and the Army Corps of Engineers. The USFS and the State of Montana are undertaking a joint review of the Montanore Project and related permits, a process that we initiated in 2004 and requires preparation of a joint EIS. In this process, the USFS completes a draft EIS, solicits and considers public comments, prepares a final EIS, undertakes a biological assessment, and initiates consultation with the U.S. Fish and Wildlife Service for the purpose of issuing a biological opinion addressing the impact of the project on threatened and endangered species, including grizzly bear, lynx and bull trout. Following the issuance of a final EIS, the USFS would issue a record of decision setting forth its decision on our proposed plan of operations and hard rock mining program. Following issuance of the record of decision, and resolution of any appeals or legal challenges to the same, we would receive the required permits from the various agencies and finalize the Montanore Project based on the results of the completed agency review.

In the second quarter of 2009, the USFS and the DEQ issued a draft EIS relating to the Montanore site for public review. The meeting for public comments on the draft EIS was held on April 16, 2009, and the public comment period expired on June 29, 2009. As part of the comment period, a site meeting occurred in June 2009 with the USFS, the DEQ, the Environmental Protection Agency, or EPA, and the Army Corps of Engineers to review the project.

The USFS and DEQ have compiled the list of public comments and issues and are responding to those issues in preparation of the final EIS. Part of the effort will be to review the technical information pertinent to the project and public comments.

The USFS and DEQ have reviewed our three-dimensional hydrologic model and are working collaboratively to determine how it can be implemented in a final EIS. This new model addresses water quantity, water quality, and other public and agency comments for the project. We have also started to initiate hydrological investigation in the Libby adit, as required by minor revisions to our Hard Rock Operating Permit 150, which will provide important technical data for the hydrologic model.

We established a $1.124 million stand-by letter of credit in early January 2007 to satisfy reclamation bonding requirements related to our planned exploration at the Libby adit. The letter of credit is secured by a $1.2 million certificate of deposit.

Additional review of the geochemical analysis completed in the draft EIS pertaining to water quality and waste rock quality is underway. We have submitted additional mine planning details to refine waste tonnages and disposal areas.

One evaluation that must be included in the final EIS involves an analysis of potential project discharges of dredged or fill material into waters of the United States, including wetlands. Such discharges are regulated by Section 404 of the Clean Water Act which requires a permit before dredged or fill material may be discharged. In connection with the Section 404 permitting process, the Army Corps of Engineers, USFS, State of Montana, and EPA are examining alternate locations for the tailings impoundment. Specifically, in selecting the least environmentally damaging practicable alternative, the relevant government agencies are evaluating the proposed locations for the construction of a tailings impoundment based on which location best affords protection of the aquatic ecosystem while enabling us to meet our project purpose.

The USFS has initiated the development of the biological assessment for the project. We continue to collect baseline data regarding fisheries, water quality, grizzly bear, and other important environmental receptors. In order to complete the last remaining portion of the biological assessment, final selection of the alignment of electricity transmission lines for the project must first be approved by the State of Montana. This will also allow the consultation process between the USFS and the U.S. Fish and Wildlife Service to commence.

If all issues are resolved satisfactorily, a record of decision approving our plan of operations could be issued by the USFS sometime in the first half of 2010.

In May 2006, McIntosh Engineering and Hatch Ltd. completed a Cost Update Study and generated a draft report for the project. This report included engineering optimization, engineering review, cost updates, mine planning, and other aspects of the project. The report also provided additional optimization opportunities that will be evaluated as part of the on-going internal engineering work currently underway.

As part of the mine planning effort, we assembled all of the geologic information developed by Noranda and another previous owner for the project and incorporated the information into the Vulcan mine modeling package. This 3-dimensional geologic model is a critical first step in further evaluating mine planning activities and projection of ore zones. This information was also used to develop the underground drilling targets for the evaluation drilling program.

Engineering refinement and geology work continues at Montanore using existing information. Geology confirmation mapping is beginning with the advance of the rehabilitation down the decline. Currently, hydrological studies are being carried out for the creation of a hydrological model for the

rock formations being crossed by the decline. Ongoing optimization and trade-off studies will help prepare assumptions that will be used in development of a feasibility study on the Montanore Project.

We may use a portion of the proceeds of this offering to finance the acquisition of mining properties, projects or companies. We are continually seeking potential acquisitions, and have engaged from time to time in discussions with companies conducting mining operations or owners of mining properties or projects. The acquisition targets vary in many respects, but all acquisitions are related to the mining of precious metals.

While we are not currently in discussions with any person or entity regarding a potential acquisition, an acquisition opportunity could arise quickly. Pursuit of potential acquisitions could result in curtailed spending or re-allocated spending with respect to the use of proceeds discussed in this prospectus supplement. See "Risk Factors—Acquisitions and business integration issues may expose us to risks" on page S-18 of this prospectus supplement.

We also own certain patented and unpatented mining claims on zinc properties in northern Washington State, referred to as the Iroquois and Advance properties. We have not conducted mining activities on these properties since the 1960s. In December 2007, we completed an impairment analysis of the carrying values of the Iroquois and Advance properties relative to their immediate development potential. In connection with that evaluation, we wrote off the capitalized costs associated with the properties in the amount of $226,000 which had been recorded in connection with mining activity that occurred in the 1950s. We continue to hold the real property, mining claims, and patented claims underlying the Iroquois and Advance properties; however, such property, mining claims, and patented claims do not have any book value in our consolidated financial statements. We also generate minor income from a working interest royalty, acquired more than 40 years ago, in several producing oil wells located in Kansas.

The net proceeds from the sale of the shares of our common stock in this offering are estimated to be approximately $ million, after deducting underwriting discounts, the discretionary fee (if any) and estimated offering expenses payable by us of $ ($ million if the underwriter's over-allotment option is exercised in full).

We intend to use the net proceeds from the sale of the common stock offered by this prospectus supplement for (i) the advanced exploration and delineation drilling program for our Montanore Project, which will include the funding of our drilling program and the preparation of a feasibility study; (ii) for the possible acquisition and exploration of new precious metals projects, properties or companies (if any); and (iii) for general corporate purposes. While we do not have any specific plans for acquisitions or other business combinations at this time, it is possible in the future we may make a decision to enter into an agreement to acquire another entity or project, in which case we may curtail spending on the use of proceeds to pursue such an acquisition or re-allocate our use of proceeds. A preliminary estimate of the allocation of the use of proceeds described above is as follows:

The actual amount that we spend in connection with each of the intended uses of proceeds may vary significantly from the amounts specified above, and will depend on a number of factors, including those described in the "Risk Factors" section beginning on page S-9 of this prospectus supplement, and, to the extent applicable, the "Risk Factors" sections in our Annual Reports on Form 10-K and our Quarterly Reports on Form 10-Q as filed with the SEC.

Until such time as the net proceeds of the offering are used as described above, we intend to invest the net proceeds primarily in U.S. treasury bills or highly liquid short-term, investment grade, interest-bearing securities.

The following table sets out our consolidated capitalization as of December 31, 2008 (audited) on an actual basis and as of September 30, 2009 (unaudited) on an actual basis and as adjusted to give effect to the receipt of net proceeds of this offering and the application of the net proceeds as described in the "Use of Proceeds" beginning on page S-25 of this prospectus supplement. This information should be read in conjunction with, and is qualified in its entirety by, our consolidated audited financial statements and notes thereto contained in our Annual Report on Form 10-K for the fiscal year ended December 31, 2008, which is incorporated by reference in this prospectus supplement.

		December 31, 2008			September 30, 2009

		Actual			Actual			As Adjusted(1)(2)
		(audited)			(unaudited)			(unaudited)
Cash and cash equivalents		$	15,448,159		$	7,710,603		$
Long-term liabilities		$	376,233		$	390,109		$	390,109
Stockholders' equity
	Preferred stock (no par value, 10,000,000 authorized)		—			—			—
	Common stock ($0.001 par value, 100,000,000 authorized; 22,920,076 shares issued and outstanding as of September 30, 2009; shares issued and outstanding as of September 30, 2009, as adjusted to give effect to this offering)(3)	$	22,757		$	22,920		$
	Additional paid-in capital	$	66,995,956		$	66,886,881		$
	Accumulated deficit	$	(1,117,306	)	$	(1,117,306	)	$	(1,117,306	)
	Deficit accumulated during the exploration stage	$	(33,847,781	)	$	(41,076,829	)	$	(41,076,829	)
	Accumulated other comprehensive loss	$	(1,624,732	)	$	(1,287,112	)	$	(1,287,112	)
Total liabilities and stockholders' equity		$	33,240,231		$	25,152,287		$

(1)

Amounts shown reflect the issuance of shares of our common stock at an offering price of $ per share in the offering. Amounts shown are net of the underwriter's discount, discretionary incentive fee (if any) and before expenses.

(2)

Assumes the underwriter's overallotment option is not exercised. If the underwriter's overallotment option were exercised in full, Cash and cash equivalents, Common stock, Additional paid-in capital and Total liabilities and stockholders' equity would be $ , $ , $ , and $ , respectively.

(3)

Excludes, as of September 30, 2009:

•: 1,710,000 shares of common stock issuable upon the exercise of stock options outstanding prior to this offering under our equity incentive plans, at a weighted average exercise price of $1.39 per share;
•: 2,565,000 shares of common stock available for future grants under our equity incentive plans; and
•: 5,300,784 shares of common stock available upon the exercise of outstanding warrants at a weighted average exercise price of $5.13 per share.

Our common stock is listed on the NYSE Amex under the symbol "MGN" and on the TSX under the symbol "MGT." On November 9, 2009, the closing price for our common stock on the NYSE Amex was $2.70 per share and the closing price on the TSX was CDN$2.88 per share.

The following table sets forth, for the periods and the stock exchanges indicated, the reported high and low market closing prices per share of our common stock.

		NYSE Amex				Toronto Stock Exchange

		High		Low		High		Low
		($)				(CDN$)
2009:
	Fourth Quarter (through November 9, 2009)		2.94		2.10		3.02		2.27
	Third Quarter		2.83		1.37		3.05		1.54
	Second Quarter		2.00		1.32		2.24		1.41
	First Quarter		2.05		1.15		2.52		1.62
2008:
	Fourth Quarter		1.79		0.57		1.90		0.70
	Third Quarter		3.25		1.29		3.29		1.14
	Second Quarter		3.87		2.64		3.93		2.75
	First Quarter		4.39		3.21		4.35		3.32
2007:
	Fourth Quarter		4.80		2.99		4.49		3.01
	Third Quarter		4.12		2.82		4.25		2.94
	Second Quarter		5.33		3.33		6.10		3.52
	First Quarter		6.44		4.53		7.50		5.11

The following is a summary of the material terms and provisions of our common stock and is qualified in its entirety by the provisions of our articles of incorporation and all amendments thereto.

We are authorized to issue 100,000,000 shares of our $0.001 par value common stock and, as of November 9, 2009, 22,944,003 shares of our common stock were issued and outstanding. Holders of our common stock are entitled to one vote per share on each matter submitted to vote at any meeting of our stockholders. Shares of common stock do not carry cumulative voting rights. Our board of directors has authority, in many instances without action by our stockholders, to issue all or any portion of the authorized but un-issued shares of common stock, which would reduce the percentage ownership of our stockholders and which would dilute the book value of our common stock.

Stockholders of our Company have no preemptive rights to acquire additional shares of common stock. The common stock is not subject to redemption and carries no subscription or conversion rights. In the event of our liquidation, the shares of common stock are entitled to share equally in corporate assets after the satisfaction of all liabilities. Holders of common stock are entitled to receive such dividends as our board of directors may from time to time declare out of funds legally available for the payment of dividends. During the last two fiscal years, we have not paid cash dividends on the common stock and we do not anticipate that we will pay cash dividends in the foreseeable future.

We and Dahlman Rose & Company, LLC have entered into an underwriting agreement dated , 2009 with respect to the shares of common stock being offered by us. Dahlman Rose & Company, LLC is acting as sole underwriter for this offering. Subject to the terms and conditions of the underwriting agreement, Dahlman Rose & Company, LLC has agreed to purchase from us, all of the shares of common stock at the public offering price less the underwriting discount set forth on the cover page of this prospectus supplement.

The underwriting agreement provides that the underwriter's obligation to purchase shares of common stock depends on the satisfaction of the conditions contained in the underwriting agreement, including:

Additionally, the obligations of the underwriter under the underwriting agreement may be terminated at the underwriter's discretion upon the occurrence of certain stated events. We have agreed to indemnify the underwriter, its affiliates, and its members, partners, directors, officers, agents, employees and representatives against certain liabilities and expenses, including liabilities under the Securities Act of 1933, as amended. We have also agreed to contribute to payments the underwriter may be required to make in respect of such liabilities.

Subject to the limitations on the size of the offering prescribed by Form S-3, described below, we have granted the underwriter an over-allotment option exercisable for 30 days from the date of the underwriting agreement to purchase a total of up to 900,000 shares of common stock, at the public offering price per share, less the underwriting discount. The underwriter may exercise this over-allotment option solely to cover any over-allotments, if any, made in connection with this offering. The total number of shares issued in this offering will be limited to such number that when multiplied by the price to the public is no greater than one-third of our public float. See "Risk Factors—Our ability to raise capital may be limited by applicable laws and regulations" on page S-17 of this prospectus supplement.

We are applying to list the shares of common stock offered hereby on the NYSE Amex and the TSX. Listing will be subject to fulfillment of all the listing requirements of the NYSE Amex and the TSX.

The underwriter has advised us that it proposes initially to offer the common stock to the public at the public offering price on the cover page of this prospectus supplement and to dealers at that price less a concession not in excess of $ per share. The underwriter may allow, and the dealers may re-allow, a discount not in excess of $ per share to other dealers. If all of the shares of common stock cannot be sold at the public offering price, the offering price and other selling terms may be changed. Any such reduction will not affect the offering proceeds received by us.

The following table shows the per share and total underwriting discount to be paid to the underwriter by us. The information assumes either no exercise or full exercise by the underwriter of its over-allotment option to purchase additional shares of common stock. The information also does not reflect an additional incentive fee of 0.50% of the gross proceeds of the offering ($ ) that may be payable by us to the underwriter at our sole discretion.

With respect to the sale of common stock under the prospectus, the maximum compensation to be received by any member of the Financial Industry Regulatory Authority, Inc. or independent broker or dealer will not be greater than 8%.

We and our officers and directors have agreed that, for a period of 90 days from the date of the underwriting agreement, we and they will not, without the prior written consent of Dahlman Rose Company, LLC, directly or indirectly, offer, sell, agree to offer or sell, solicit offers to purchase, grant any call option or purchase any put option with respect to, pledge, borrow or otherwise dispose of any shares of common stock or any securities convertible into or exchangeable for shares of common stock, and will not establish or increase any "put equivalent position" or liquidate or decrease any "call equivalent position" with respect to any shares of common stock or any securities convertible into or exchangeable for shares of common stock (in each case within the meaning of Section 16 of the Exchange Act and the rules and regulations promulgated thereunder), or otherwise enter into any swap, derivative or other transaction or arrangement that transfers to another, in whole or in part, any economic consequence of ownership of any of shares of common stock or any securities convertible into or exchangeable for shares of common stock.

In connection with the offering, the underwriter may purchase and sell our common stock in the open market. These transactions may include short sales, stabilizing transactions and purchases to cover positions created by short sales. Short sales involve the sale by an underwriter of a greater number of shares than it is required to purchase in the offering. "Covered" short sales are sales made in an amount not greater than the underwriter's over-allotment option to purchase additional shares of common stock from us in the offering. The underwriter may close out any covered short position by either exercising the over-allotment option to purchase additional shares or purchasing shares in the open market. In determining the source of shares of common stock to close out the covered short position, the underwriter will consider, among other things, the price of common stock available for purchase in the open market as compared to the price at which the underwriter may purchase additional shares of common stock pursuant to the over-allotment option. "Naked" short sales are any sales in excess of such over-allotment option. The underwriter must close out any naked short position by purchasing shares of common stock in the open market. A naked short position is more likely to be created if the underwriter is concerned that there may be downward pressure on the price of the common stock in the open market after pricing that could adversely affect investors who purchase in the offering. Stabilizing transactions consist of various bids for or purchases of common stock made by the underwriter in the open market prior to the completion of the offering.

Purchases to cover a short position and stabilizing transactions, as well as other purchases by the underwriter for its own account, may have the effect of preventing or delaying a decline in the market price of shares of our common stock, and may stabilize, maintain or otherwise affect the market price of our common stock. As a result, the price of our common stock may be higher than the price that otherwise might exist in the open market. If these activities are commenced, they may be discontinued at any time. These transactions may be effected on the NYSE Amex or the TSX, in the over-the-counter market or otherwise.

This prospectus supplement and the accompanying base prospectus in electronic format may be made available on Internet sites or through other online services maintained by the underwriter, or by its affiliates. Other than any prospectus supplement and the accompanying base prospectus made available in electronic format in this manner, the information on any website containing this prospectus supplement and the accompanying base prospectus is not part of this prospectus supplement, the accompanying base prospectus or the registration statement of which this prospectus supplement forms a part, and such information has not been approved or endorsed by us or the underwriter in such capacity and should not be relied on by prospective investors.

The underwriting agreement will be included as an exhibit to a current report on Form 8-K that will be filed with the SEC in connection with the consummation of this offering.

We estimate that our share of the total expenses of the offering, excluding the underwriting discount and the discretionary fee (if any), will be approximately $ , which includes approximately $ in reimbursable expenses paid to the underwriter.

Dahlman Rose Company, LLC may in the future engage in investment banking and other commercial dealings in the ordinary course of business with us. It would receive customary fees and commissions for these engagements, if any.

The common stock may also be offered to a limited number of accredited investors (as defined under Canadian Securities laws) on a private placement basis in Canada.

THE UNDERWRITER HAS AGREED THAT IT WILL NOT, DIRECTLY OR INDIRECTLY, OFFER, SELL, AGREE TO OFFER OR SELL, SOLICIT OFFERS TO PURCHASE OR SELL, DELIVER, OR OTHERWISE DISPOSE OF ANY COMMON STOCK PURCHASED BY IT IN CANADA OR TO RESIDENTS OF CANADA EXCEPT PURSUANT TO AN EXEMPTION FROM THE PROSPECTUS REQUIREMENTS OF APPLICABLE CANADIAN SECURITIES LAWS AND IN ACCORDANCE WITH THE DEALER REGISTRATION REQUIREMENTS OF APPLICABLE CANADIAN SECURITIES LAWS OR PURSUANT TO AN EXEMPTION FROM SUCH REQUIREMENTS. ANY SELLING AGREEMENT OR SIMILAR AGREEMENT WITH RESPECT TO THE COMMON STOCK WILL REQUIRE EACH DEALER OR OTHER PARTY THERETO TO MAKE AN AGREEMENT TO THE SAME EFFECT.

Canadian purchasers of the common stock will receive definitive certificates registered to them which will be inscribed with legends prescribed by Canadian securities laws and the TSX setting forth the resale restrictions and hold periods applicable to such Canadian stock acquired by the Canadian purchasers.

In relation to each member state of the European Economic Area that has implemented the Prospectus Directive (each, a relevant member state), with effect from and including the date on which the Prospectus Directive is implemented in that relevant member state (the relevant implementation date), an offer of securities described in this prospectus supplement may not be made to the public in that relevant member state prior to the publication of a prospectus in relation to the securities that has been approved by the competent authority in that relevant member state or, where appropriate, approved in another relevant member state and notified to the competent authority in that relevant member state, all in accordance with the Prospectus Directive, except that, with effect from and including the relevant implementation date, an offer of securities described in this prospectus supplement may be made to the public in that relevant member state at any time:

Each purchaser of securities described in this prospectus supplement located within a relevant member state will be deemed to have represented, acknowledged and agreed that it is a "qualified investor" within the meaning of Article 2(1)(e) of the Prospectus Directive.

For purposes of this provision, the expression an "offer to the public" in any relevant member state means the communication in any form and by any means of sufficient information on the terms of the offer and the securities to be offered so as to enable an investor to decide to purchase or subscribe for the securities, as the expression may be varied in that member state by any measure implementing the Prospectus Directive in that member state, and the expression "Prospectus Directive" means Directive 2003/71/EC and includes any relevant implementing measure in each relevant member state.

We have not authorized and do not authorize the making of any offer of common stock through any financial intermediary on our behalf, other than offers made by the underwriter with a view to the final placement of the securities as contemplated in this prospectus supplement. Accordingly, no purchaser of the common stock, other than the underwriter, is authorized to make any further offer of the common stock on behalf of us or the underwriter.

This prospectus supplement is only being distributed to, and is only directed at, persons in the United Kingdom that are qualified investors within the meaning of Article 2(1)(e) of the Prospectus Directive that are also (i) investment professionals falling within Article 19(5) of the Financial Services and Markets Act 2000 (Financial Promotion) Order 2005 (the "Order") or (ii) high net worth entities, and other persons to whom it may lawfully be communicated falling within Article 49(2)(a) to (d) of the Order (each such person being referred to as a relevant person). This prospectus supplement and its contents are confidential and should not be distributed, published or reproduced (in whole or in part) or disclosed by recipients to any other persons in the United Kingdom. Any person in the United Kingdom that is not a relevant person should not act or rely on this prospectus supplement or any of its contents.

Neither this prospectus supplement nor any other offering material relating to the securities offered hereby has been submitted to the clearance procedures of the Autorité des Marchés Financiers or of the competent authority of another member state of the European Economic Area and notified to the Autorité des Marchés Financiers. The common stock has not been offered or sold and will not be offered or sold, directly or indirectly, to the public in France. Neither this prospectus supplement nor any other offering material relating to the common stock offered hereby has been or will be:

The common stock may be resold, directly or indirectly, only in compliance with articles L.411-1, L.411-2, L.412-1 and L.621-8 through L.621-8-3 of the French Code monétaire et financier.

The following is a summary of the anticipated material U.S. federal income tax consequences regarding the acquisition, ownership and disposition of our common stock. This summary applies to you only if you hold such common stock as a capital asset. This summary is based upon the U.S. Internal Revenue Code of 1986, as amended, which we refer to as the Code, regulations promulgated under the Code, and administrative rulings and judicial decisions related thereto. Changes in the laws may alter the tax treatment of the ownership and disposition of our common stock, possibly with retroactive effect.

This summary is general in nature and does not address the effects of any state or local taxes, estate taxes, or the tax consequences in jurisdictions other than the United States. In addition, it does not address all tax consequences that may be relevant to you in your particular circumstances, nor does it apply to you if you are a holder with a special status, such as:

If a partnership (including for this purpose any entity treated as a partnership for U.S. federal income tax purposes) holds our common stock, the tax treatment of a partner will generally depend upon the status of the partner and upon the activities of the partnership. A partner of a partnership that owns or may acquire our common stock should consult the partner's tax advisor regarding the specific tax consequences of the acquisition and ownership of our common stock.

YOU SHOULD CONSULT YOUR OWN ADVISOR REGARDING THE TAX CONSEQUENCES OF THE OWNERSHIP AND DISPOSITION OF OUR COMMON STOCK IN LIGHT OF YOUR PARTICULAR CIRCUMSTANCES.

The following discussion applies to you if you are a "U.S. Holder." For purposes of this discussion, a "U.S. Holder" means a beneficial owner of a share of our common stock that is, for U.S. federal income tax purposes:

If you sell or otherwise dispose of our common stock (or are deemed to have sold or disposed of them) in a taxable disposition:

Long-term capital gains of noncorporate taxpayers, including individuals, are generally subject to a 15% maximum U.S. federal income tax rate for capital gains recognized in taxable years beginning before January 1, 2011. The deductibility of capital losses is subject to limitations.

The following summary applies to you if you are a "non-U.S. Holder" of our common stock. A "non-U.S. Holder" is a beneficial owner of a share of our common stock that is not a U.S. Holder.

We do not expect to make distributions on our common stock in the foreseeable future. The gross amount of distributions, if any, payable by us on our common stock generally would be treated as dividend income to the extent paid out of current or accumulated earnings and profits. A distribution on our stock in excess of current and accumulated earnings and profits will be treated as a tax-free return of capital to the extent of the Non-U.S. Holder's adjusted basis in such stock, and any additional excess will generally be subject to U.S. federal income tax in the manner described in "—Gain on Sale or Other Disposition of Common Stock," immediately below. However, dividends that are effectively connected with the conduct of a trade or business by the non-U.S. Holder within the United States or, if required by an applicable income tax treaty, are attributable to a permanent establishment maintained by the non-U.S. Holder in the United States, are not subject to such withholding tax, provided certain certification and disclosure requirements are satisfied. Instead, such dividends are subject to U.S. federal income tax on a net income basis in the same manner as if the non-U.S. Holder were a United States person as defined under the Code, unless an applicable income tax treaty provides otherwise. Any such effectively connected dividends received by a foreign corporation may be subject to an additional "branch profits tax" at a 30% rate or such lower rate as may be specified by an applicable income tax treaty. If we are a "U.S. real property holding corporation" as described below, distributions to Non-U.S. Holders that are not dividends will be subject to withholding of U.S. federal income tax at a 10% rate. If we are a "U.S. real property holding corporation" as described below, distributions to Non-U.S. Holders that are not dividends will be subject to withholding of U.S. federal income tax at a 10% rate. Any such withholding tax will be creditable against the Non-U.S. Holder's U.S. income tax liability, and a Non-U.S. Holder may be able to claim a refund for any such withholding taxes imposed on return of capital distributions up to the Non-U.S. Holder's adjusted tax basis in our shares, if such Non-U.S. Holder files a federal income tax return.

To claim the benefit of an applicable treaty rate or to claim exemption from withholding because the income is effectively connected with the conduct of a trade or business in the United States, a non-U.S. Holder must provide a properly executed Internal Revenue Service Form W-8BEN for treaty benefits or Form W-8ECI for effectively connected income, or such successor forms as the Internal Revenue Service designates, prior to the payment of dividends. Special certification and other requirements apply to certain non-U.S. Holders that are pass-through entities rather than corporations or individuals.

A non-U.S. Holder of our common stock eligible for a reduced rate of U.S. withholding tax pursuant to an income tax treaty may obtain a refund of any excess amounts withheld by filing an appropriate and timely claim for refund with the Internal Revenue Service.

Any gain realized on the disposition of our common stock will generally not be subject to U.S. federal income tax unless:

An individual non-U.S. Holder described in the first bullet point immediately above will be subject to tax on the net gain derived from the sale under regular graduated United States federal income tax rates. An individual non-U.S. Holder described in the second bullet point immediately above will be subject to a flat 30% tax on the gain derived from the sale, which may be offset by United States source capital losses, even though the individual is not considered a resident of the United States. If a non-U.S. Holder that is a foreign corporation falls under the first bullet point immediately above, it will be subject to tax on its net gain in the same manner as if it were a United States person as defined under the Code and, in addition, may be subject to the branch profits tax equal to 30% of its effectively connected earnings and profits or at such lower rate as may be specified by an applicable income tax treaty.

With respect to third bullet point above, we believe that we currently are, and expect to be for the foreseeable future, a USRPHC. However, so long as our common stock is regularly traded on an established securities market, a non-U.S. Holder will not recognize taxable gain on a sale of our common stock under the third bullet point above unless the non-U.S. Holder recognizes gain on the sale of our common stock, and actually or constructively owns more than 5% of our common stock at any time during the five-year period ending on the date of disposition or, if shorter, the non-U.S. Holder's holding period for the common stock.

Dividend payments made with respect to shares of our common stock and proceeds from the sale, exchange or other disposition of shares of our common stock may be subject to information reporting requirements, and to possible U.S. backup withholding (currently at a rate of 28%).

In general, backup withholding will apply with respect to reportable payments made to a U.S. Holder unless (i) the U.S. Holder is a corporation or other exempt recipient and, if required, demonstrates such exemption, or (ii) the U.S. Holder furnishes the payor with a taxpayer identification number on IRS Form W-9 in the manner required, certifies under penalty of perjury that such U.S. Holder is not currently subject to backup withholding and otherwise complies with the backup withholding requirements.

A Non-U.S. Holder may be required to certify as to its non-U.S. status on IRS Form W-8BEN (or other applicable form) in order to establish an exemption from backup withholding. The payment of proceeds of a sale of common stock effected by or through a U.S. office of a broker is subject to both backup withholding and information reporting unless you provide the payor with your name and address and you certify your non-U.S. status or otherwise establish an exemption from such withholding. In general, backup withholding and information reporting will not apply to the payment of the proceeds of a sale of common stock by or through a foreign office of a broker. If, however, such broker is, for U.S. federal income tax purposes, a U.S. person, a controlled foreign corporation, a foreign person that derives 50% or more of its gross income for certain periods from the conduct of a trade or business in the United States or a foreign partnership that at any time during its tax year either is engaged in the conduct of a trade or business in the United States or has as partners one or more U.S. persons that, in the aggregate, hold more than 50% of the income or capital interests in the partnership, backup withholding will not apply but such payments nonetheless will be subject to information reporting, unless such broker has documentary evidence in its records that you are a Non-U.S. Holder and certain other conditions are met or you otherwise establish an exemption.

Backup withholding is not an additional tax. Rather, the amount of any backup withholding imposed on a payment to a holder will be allowed as a refund or a credit against such holder's U.S. federal income tax liability, provided that the required information is furnished to the IRS.

Certain legal matters in connection with the common stock offered hereby will be passed upon on behalf of Mines Management by Davis Graham & Stubbs LLP, Denver, Colorado and on behalf of the underwriter by Troutman Sanders LLP, Virginia Beach, Virginia.

Our audited consolidated financial statements as of and for the year ended December 31, 2008, included in our Annual Report on Form 10-K for the year ended December 31, 2008, have been audited by the independent registered public accounting firm Tanner LC. Our audited consolidated financial statements as of December 31, 2007 and for the years ended December 31, 2007 and 2006, included in our Annual Report on Form 10-K for the year ended December 31, 2008, have been audited by LeMaster & Daniels PLLC, an independent registered public accounting firm. Each of Tanner LC and LeMaster & Daniels PLLC are independent of us in accordance with the rules of the Public Company Accounting Oversight Board and in accordance with the applicable rules and regulations of the SEC. Each of our audited consolidated financial statements are incorporated herein by reference to the extent and for the period set forth in and in reliance upon the reports given on the authority of Tanner LC and LeMaster & Daniels PLLC as experts in accounting and auditing.

The statements as to our mineralized material and mineral resources which appear or are incorporated by reference herein, have been derived from reports, statements, or opinions prepared or certified by Steve Ristorcelli and David C. Fitch of MDA and have been so included or incorporated upon the authority as experts of Steve Ristorcelli and David C. Fitch of MDA, to the extent described herein or in the documents incorporated by reference herein.

Common Stock
Preferred Stock Purchase Rights
Preferred Stock
Warrants
Convertible Debt Securities
Debt Securities
Rights
Units

Mines Management, Inc. may offer and sell from time to time up to $65,000,000 of its shares of common stock, par value $0.001, preferred stock purchase rights, shares of preferred stock, without par value, warrants, convertible debt securities, debt securities, rights or units or any combination of these securities, in one or more transactions on terms to be determined at the time of sale.

This prospectus provides you with a general description of the securities that we may offer. Each time that securities are offered and sold by us using this prospectus, we will provide a supplement to this prospectus that contains specific information about the offering, including the offering price of the securities. The supplement may also add, update or change information contained in this prospectus. You should read both this prospectus and the prospectus supplement, together with any additional information which is incorporated by reference into this prospectus before you invest in our securities.

We may sell the securities to or through underwriters, dealers or agents or directly to purchasers on a continuous or delayed basis. The prospectus supplement, which we will provide to you each time we offer securities, will set forth the names of any underwriters, dealers or agents involved in the sale of the securities, and any applicable fee, commission or discount arrangements with them. For additional information on the methods of sale, you should refer to the section entitled "Plan of Distribution" in this prospectus.

Our common stock is listed on the NYSE Amex LLC, which we refer to in this prospectus as the NYSE Amex, under the symbol "MGN" and on the Toronto Stock Exchange under the symbol "MGT." On October 15, 2009, the closing price for our common stock on the NYSE Amex was $2.66 per share and the closing price on the Toronto Stock Exchange was Cdn$2.75 per share. As of October 15, 2009, the aggregate market value of our outstanding common stock held by non-affiliates, or the public float, was approximately $49,090,183, which was calculated based on 18,454,956 shares of outstanding common stock held by non-affiliates and on a price per share of $2.66, the closing price of our common stock on the NYSE Amex on October 15, 2009. Pursuant to General Instruction I.B.6 of Form S-3, in no event will we sell our common stock in a public primary offering with a value exceeding more than one-third of our public float in any 12-month period so long as our public float remains below $75.0 million. We have not offered any securities pursuant to General Instruction I.B.6 of Form S-3 during the 12 calendar months prior to and including the date of this prospectus.

This prospectus may not be used to offer and sell securities unless accompanied by the applicable prospectus supplement.

Investing in our securities involves risks. For a discussion of certain risks that should be considered by prospective investors, see "Risk Factors" beginning on page 8 of this prospectus.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or determined if this prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

As used in this prospectus, the terms "Mines Management," "we," "our," "ours" and "us" may, depending on the context, refer to Mines Management, Inc. or to one or more of Mines Management, Inc.'s consolidated subsidiaries or to Mines Management, Inc. and its consolidated subsidiaries, taken as a whole. When we refer to "shares" throughout this prospectus, we include all rights attaching to our shares of common stock under any shareholder rights plan then in effect.

References in this prospectus to "$" are to United States dollars. Canadian dollars are indicated by the symbol "Cdn$".

This prospectus is part of a registration statement that we filed with the Securities and Exchange Commission, which we sometimes refer to in this prospectus as the SEC, using a "shelf" registration process on Form S-3. Under the shelf registration, we may sell any combination of the securities described in this prospectus in one or more offerings up to a total dollar amount of $65,000,000.

This prospectus provides you with a general description of the securities that we may offer. Each time that we sell securities, we will provide a prospectus supplement that will contain specific information about the terms of that offering. The prospectus supplement also may add, update or change information contained in this prospectus. You should read both this prospectus and any prospectus supplement together with additional information incorporated by reference in this prospectus before making an investment in our securities. See "Where You Can Find More Information" below for more information. We may use this prospectus to sell securities only if it is accompanied by a prospectus supplement.

You should rely only on information contained or incorporated by reference in this prospectus. We have not authorized anyone to provide you with information different from that contained or incorporated in this prospectus. If anyone provides you with different or inconsistent information, you should not rely on it. You should not assume that the information appearing in this prospectus, any prospectus supplement or any document incorporated by reference is accurate at any date other than as of the date of each such document. Our business, financial condition, results of operations and prospects may have changed since the date indicated on the cover page of such documents. The distribution of this prospectus may be restricted by law in certain jurisdictions. You should inform yourself about and observe any of these restrictions. This prospectus does not constitute, and may not be used in connection with, an offer or solicitation by anyone in any jurisdiction in which the offer or solicitation is not authorized, or in which the person making the offer or solicitation is not qualified to do so, or to any person to whom it is unlawful to make the offer or solicitation.

The registration statement of which this prospectus is a part, including the exhibits to the registration statement, contains additional information about us and the securities offered under this prospectus. That registration statement can be read at the SEC's website, located at www.sec.gov, or at the SEC's offices referenced under the heading "Where You Can Find More Information."

We file annual, quarterly and current reports, proxy statements and other information with the SEC. You may read and copy any of these documents at the SEC's public reference room at 100 F Street N.E., Room 1580, Washington, D.C. 20549. Please call the SEC at 1-800-SEC-0330 for further information on the public reference room. Our SEC filings are also available to the public at the SEC's website at www.sec.gov.

The SEC allows us to "incorporate by reference" the information we file with the SEC, which means that we can disclose important information in this prospectus by referring you to the document that contains the information. We hereby incorporate by reference the documents listed below, which were previously filed with the SEC, and any future filings made with the SEC under Sections 13(a), 13(c), 14 or 15(d) of the Securities Exchange Act of 1934, as amended, which we sometimes refer to in this prospectus as the Exchange Act, other than information in a Current Report on Form 8-K furnished pursuant to Item 2.02 or Item 7.01 of Form 8-K and exhibits filed in connection with such information:

In addition, all reports and documents filed by us pursuant to the Exchange Act, other than information in a Current Report on Form 8-K furnished pursuant to Item 2.02 or Item 7.01 of Form 8-K and exhibits filed in connection with such information, after the date of the initial filing of this registration statement on Form S-3 to which this prospectus relates and prior to the time that we sell all the securities offered by this prospectus shall be deemed to be incorporated by reference into this prospectus.

Any statement contained in a document incorporated or deemed to be incorporated by reference in this prospectus shall be deemed modified, superseded or replaced, as applicable, for purposes of this prospectus to the extent that a statement contained in this prospectus, or in any subsequently filed document that also is deemed to be incorporated by reference in this prospectus, modifies, supersedes or replaces such statement. Any statement so modified, superseded or replaced shall not be deemed, except as so modified, superseded or replaced, to constitute a part of this prospectus. Subject to the foregoing, all information appearing in this prospectus is qualified in its entirety by the information appearing in the documents incorporated by reference.

Statements contained in this prospectus as to the contents of any contract or other document are not necessarily complete, and in each instance we refer you to the copy of the contract or document filed as an exhibit to the registration statement or the documents incorporated by reference in this prospectus, each such statement being qualified in all respects by such reference.

You may receive a copy of any of these filings, at no cost, by writing or calling James H. Moore, Vice President and Chief Financial Officer, Mines Management, Inc., 905 W. Riverside Avenue, Suite 311, Spokane, Washington 99201, telephone (509) 838-6050 or by contacting the SEC as described above.

CAUTIONARY NOTE TO UNITED STATES INVESTORS CONCERNING ESTIMATES OF
MEASURED, INDICATED AND INFERRED RESOURCES

The terms "mineral resource," "measured mineral resource," "indicated mineral resource" and "inferred mineral resource" that are used in documents incorporated by reference into this prospectus are defined in and required to be disclosed by Canadian National Instrument 43-101—Standards of Disclosure for Mineral Projects, commonly known as NI 43-101; however, these terms are not recognized under SEC Industry Guide 7 and are normally not permitted to be used in reports and registration statements filed with the SEC. U.S. investors are cautioned not to assume that all or any part of mineral deposits in these categories will ever be converted into reserves. "Inferred mineral resources" have a great amount of uncertainty as to their existence, and great uncertainty as to their economic and legal feasibility. Investors are cautioned not to assume that all or any part of an inferred mineral resource exists or is economically or legally mineable or will ever be upgraded to a higher category. Disclosure of "contained ounces" in a resource is permitted disclosure under Canadian regulations; however, the SEC normally only permits issuers to report mineralization that does not constitute "reserves" by SEC standards as in place tonnage and grade without reference to unit measures. Accordingly, information included or incorporated by reference in this prospectus and any prospectus supplement or free writing prospectus contains descriptions of our mineral deposits that may not be comparable to similar information made public by U.S. companies subject to the reporting and disclosure requirements under only United States federal securities laws and the rules and regulations promulgated thereunder.

We are engaged in the business of acquiring and exploring mining properties. None of our properties are currently in production, and, consequently, we have no current operating income or operating cash flow. Accordingly, no ratios are shown for any of the years ended December 31, 2004, 2005, 2006, 2007 and 2008 as earnings were not sufficient to cover fixed charges. As of the date of this prospectus, we have not issued any preferred stock. We did not have any material amount of indebtedness for which interest payments were required during the years ended December 31, 2004, 2005, 2006, 2007 or 2008, and, therefore the amount by which earnings were inadequate to cover fixed charges was not material.

This prospectus, including the information incorporated by reference in this prospectus, contains forward-looking statements as defined in Section 27A of the Securities Act of 1933, as amended, which we sometimes refer to in this prospectus as the Securities Act, Section 21E of the Exchange Act, and the Private Securities Litigation Reform Act of 1995, with respect to our financial condition, business, prospects, plans, objectives, goals, potential acquisitions, strategies, future events, capital expenditures, and exploration efforts. The use of any statements containing the words "development," "intend," "believe," "estimate," "project," "expect," "anticipate," "plan," "should" or similar expressions are intended to identify such statements. These statements include, among other things, comments regarding further exploration and evaluation of the Montanore Project, including planned rehabilitation and extension of the Libby adit, drilling activities, feasibility determination, engineering studies, environmental and permitting requirements, process and timing; estimates of mineralized material and measured, indicated and inferred resources; financing needs; plans to acquire other exploration properties or other companies; planned expenditures in 2009 and 2010; potential completion of a bankable feasibility study; and the markets for silver and copper.

Although we believe that our plans, intentions and expectations reflected in these forward-looking statements are reasonable, we cannot be certain that these plans, intentions or expectations will be achieved. Actual results, performance or achievements could differ materially from those contemplated,

expressed or implied by the forward-looking statements contained or incorporated by reference in this prospectus. Disclosure of important factors that could cause actual results to differ materially from our plans, intentions or expectations are included under the heading "Risk Factors" in this prospectus and our Annual Report on Form 10-K for the year ended December 31, 2008.

Forward-looking statements inherently involve risks and uncertainties that could cause actual results to differ materially from the forward-looking statements. Factors that could cause or contribute to such differences include, but are not limited to, worldwide economic and political events affecting the supply of and demand for silver and copper, volatility in the market price for silver and copper, financial market conditions and the availability of financing on terms acceptable to Mines Management, Inc., uncertainty regarding whether reserves will be established at our Montanore Project, uncertainties associated with developing new mines, variations in ore grade and other characteristics affecting mining, crushing, milling and smelting and mineral recoveries, geological, technical, permitting, mining and processing problems, the availability, terms, conditions and timing of required governmental permits and approvals, uncertainty regarding future changes in applicable law or implementation of existing law, the availability of experienced employees, uncertainties regarding the availability of properties or companies to be acquired, the ability to negotiate acquisitions on acceptable terms or to otherwise accomplish such acquisitions, the ability to finance such acquisitions on acceptable terms, and other risks and uncertainties set forth below under the caption "Risk Factors" in this prospectus and in our periodic report filings with the SEC.

Many of these factors are beyond our ability to control or predict. These factors are not intended to represent a complete list of the general or specific factors that may affect us. We may note additional factors elsewhere in this prospectus and in any documents incorporated by reference into this prospectus. All forward-looking statements speak only as of the date made. All subsequent written and oral forward-looking statements attributable to us, or persons acting on our behalf, are expressly qualified in their entirety by the cautionary statements. Except as required by law, we undertake no obligation to update any forward-looking statement.

Mines Management, Inc. is engaged in the business of acquiring and exploring, and if exploration is successful, developing mineral properties, primarily those containing silver and associated base and precious metals. Mines Management, Inc. was incorporated under the laws of the State of Idaho on February 20, 1947. Our principal executive offices are located at 905 W. Riverside, Suite 311, Spokane, Washington 99201, and the telephone number at that office is (509) 838-6050. Our Internet address is www.minesmangement.com. Information contained on our website is not a part of this prospectus or the documents incorporated herein by reference.

Our principal mineral property interest is held by one of our wholly owned subsidiaries, Newhi, Inc., and is referred to as the Montanore Project. The Montanore property is currently in the exploration stage. We have commenced re-permitting of the Montanore Project and are determining its feasibility for development. None of our properties are currently in production.

Our common stock is listed on the NYSE Amex under the symbol "MGN" and on the Toronto Stock Exchange under the symbol "MGT."

The Montanore Project is located in northwestern Montana, and between 1988 and 2002 was owned by Noranda Minerals Corporation, which we sometimes refer to in this prospectus as Noranda. During that time the project received a record of decision from the United States Forest Service and the State of Montana, allowing Noranda to proceed with full operations, but the project was never put into operation. In addition, all other major permits required for the project were also issued during this time period. From 1988 to 2002, we held royalty rights to a portion of the deposit. In 2002, Noranda announced that it was abandoning the project, and subsequently transferred to us by quitclaim deed the patented and unpatented mining claims that control the mineral rights, and all drill core and intellectual property, including geologic, environmental and engineering studies, relating to the Montanore Project.

In May 2006, we acquired two Noranda subsidiaries that held title to the Montanore property providing access to the 14,000 foot Libby adit and related permits. Through this acquisition, we also received the State of Montana operating permit for the Montanore Project. In March 2008, we obtained authorization from the State of Montana to resume the exploration activities started by Noranda. We submitted revisions that allowed us to reopen the Libby adit and to dewater and rehabilitate the adit. The Libby adit, when extended, will provide access to the Montanore deposit for our planned underground evaluation drilling program. We reopened the Libby adit in June 2006 and water sampling and testing were completed in July 2006.

In November 2006, we received another permit revision approval allowing us to proceed with our planned underground evaluation drilling program at the Montanore Project. This advanced exploration and delineation drilling program includes the following: development and advancement of the Libby adit by 3,000 feet to access the deposit, drifting of approximately 10,000 feet and establishment of drill stations, and diamond core drilling of approximately 45,000 feet among approximately 50 holes. Results of the drill program, if successful, are expected to provide data to assist in completion of a bankable feasibility study and further optimization of the mine plan.

Also, in the fourth quarter of 2006, we purchased a site generator and erected a warehouse building at the Libby adit site, along with an office and employee change facility. We established a $1.1 million stand-by letter of credit in early January 2007 to satisfy reclamation bonding requirements related to our planned exploration at the Libby adit.

In 2007, we completed the construction of site infrastructure to support our planned underground evaluation program at the Montanore Project. This included the design, engineering and construction of a $1.3 million water treatment plant to process all water pumped out of the adit. The utility design was completed and an initial order of electrical supplies, ventilation material, pumping equipment, and ground control roof bolts and supplies have been delivered to the site. Construction of a dry storage structure for inventory was completed in the fall of 2007.

The initial fleet of surface equipment and underground equipment was purchased at a cost in excess of $6 million and delivered in the third and fourth quarters of 2007. In 2008, we continued the testing and installation of the adit dewatering system in preparation for the planned 3,000 foot extension and initiation of the drilling program. Other preparations for the commencement of drifting and delineation drilling included the retention of Small Mine Development, which managed the adit advancement and the drilling program, engineering for a new nitrate circuit addition to the water treatment facility and installation of the initial sumps and pumping system, consisting of two declining drifts approximately 15 × 15 in section and 80 feet long each. Two sumps were placed into service during the third quarter of 2008. These sumps are part of the overall dewatering system designed to clarify water from the adit before sending it to the water treatment plant on the surface. Construction of the sumps allowed us to test most of the mining equipment that will be used during the adit advancement and future development activities.

Current operations on the Libby adit include continued operations on the Montanore site water treatment system and dewatering of the decline. After completion of the 7,200 foot level sump and decanting system, Small Mine Development, the adit rehabilitation contractor, was demobilized April 30, 2009 as an expenditure conservation measure pending completion of the permitting process that, once complete, will allow us to move forward with our planned underground evaluation drilling program. To date, infrastructure placed in the decline includes a refuge chamber, mine power center and temporary pump station along with the previously installed sumps and pumping system at the 700 ft. location. The decline is now in a standby mode until the environmental review progresses, as discussed below.

In order to advance the Montanore Project past the exploration stage, we must obtain the requisite project approvals and permits from the U.S. Forest Service, the State of Montana, and the Army Corps of Engineers. The U.S. Forest Service determined that the exploration activities approved by the State of Montana required its approval as well and determined the review process should be incorporated into the current environmental impact statement process for the full project. The U.S. Forest Service and the State of Montana are undertaking a joint review of the Montanore Project and related permits, a process that we initiated in 2004 and generally takes a number of years to complete. A central element of the federal and state project review is the completion of a thorough environmental review process, which will be documented in a joint Environmental Impact Statement, which we sometimes refer to in this prospectus as the EIS. Prior to issuance of a record of decision, the U.S. Forest Service is required to complete a draft EIS, solicit and consider public comments, prepare a final EIS, undertake a biological assessment, and initiate consultation with the U.S. Fish and Wildlife Service for the purpose of issuing a biological opinion addressing the impact of the project on threatened and endangered species, including grizzly bear, lynx and bull trout. Following the issuance of a final EIS, the U.S. Forest Service would issue a record of decision setting forth its decision on our proposed plan of operations and hard rock mining program. Following issuance of the record of decision, and resolution of any appeals or legal challenges to the same, we would receive the required permits from the various agencies and finalize the Montanore Project based on the results of the completed agency review.

In the second quarter of 2009, the U.S. Forest Service and the Montana Department of Environmental Quality, which we sometimes refer to in this prospectus as the agencies, issued a draft EIS for public review relating to the Montanore site. The meeting for public comments on the draft

EIS was held on April 16, 2009, and the public comment period expired, after an extension of the period by the agencies, on June 29, 2009. As part of the comment period, a site meeting occurred in June 2009 with the agencies, the Environmental Protection Agency, which we refer to as the EPA in this prospectus, and the Army Corps of Engineers to review the project.

The agencies have compiled the list of public comments and issues and are responding to those issues in preparation of the final EIS. Part of the effort will be to review the technical information pertinent to the project and public comments. This portion of the effort is currently underway.

The agencies have reviewed our three-dimensional hydrologic model and are working collaboratively to determine how it can be implemented in a final EIS. This new model addresses water quantity, water quality, and other public and agency comments for the project. We have also started to initiate hydrological investigation in the Libby adit, as required by minor revisions to our Hard Rock Operating Permit 150, which will provide important technical data for the hydrologic model.

One evaluation that must be included in the final EIS involves an analysis of potential project discharges of dredged or fill material into waters of the United States, including wetlands. Such discharges are regulated by Section 404 of the Clean Water Act which requires a permit before dredged or fill material may be discharged. In connection with the Section 404 permitting process, the tailings alternatives for the Montanore Project are currently being reviewed by the Army Corps of Engineers, U.S. Forest Service, State of Montana, and EPA. Specifically, in selecting the least environmentally damaging practicable alternative, the relevant government agencies are evaluating the proposed locations for the construction of a tailings impoundment based on which location best affords protection of the aquatic ecosystem while enabling us to meet our project purpose.

The U.S. Forest Service has initiated the development of the biological assessment for the project. In order to complete the last remaining portion of the biological assessment, final selection of the alignment of electricity transmission lines for the project must first be approved by the State of Montana. This will also allow the consultation process between the U.S. Forest Service and the U.S. Fish and Wildlife Service to commence.

If all issues are resolved satisfactorily, the overall project permitting schedule anticipates that a record of decision could be issued by the U.S. Forest Service sometime in the first half of 2010.

Engineering and geology work continues at Montanore using existing information. Geology confirmation mapping is beginning with the advance of the rehabilitation down the decline. Currently, hydrological studies are being carried out for the creation of a hydrological model for the rock formations being crossed by the decline. Ongoing optimization and trade-off studies will help prepare assumptions that will be used in development of a feasibility study on the Montanore Project.

Engineering for the nitrate removal addition to the water treatment system is complete with construction on hold pending receipt of the final EIS and record of decision. Construction of the nitrate system is scheduled to start and be completed prior to beginning the final section of the adit to reach the ore body and install drill stations. The current schedule is to begin construction of the concrete chambers in late April/early May of 2010 based on timing of receipt of the record of decision following completion of a final EIS.

We also own certain patented and unpatented mining claims on zinc proprieties in northern Washington state, which we sometimes refer to in this prospectus as the Iroquois and Advance

properties. We have not conducted mining activities on these properties since the 1960s. In December 2007, we completed an impairment analysis of the carrying values of the Iroquois and Advance properties relative to their immediate development potential. In connection with that evaluation, we wrote off the capitalized costs associated with the properties in the amount of $226,000 which had been recorded in connection with mining activity that occurred in the 1950s. We continue to hold the real property, mining claims, and patented claims underlying the Iroquois and Advance properties; however, such property, mining claims, and patented claims do not have any book value in our consolidated financial statements. We also generate minor income from a working interest royalty, acquired more than 40 years ago, in several producing oil wells located in Kansas.

An investment in the securities offered hereby involves a high degree of risk. You should consider the risk factors set forth below and the other information in this prospectus before purchasing any of our securities. In addition to historical information, the information in this prospectus contains "forward-looking" statements about our future business and performance. Our actual operating results and financial performance may be very different from what we expect as of the date of this prospectus. The risks below address some of the factors that may affect our future operating results and financial performance.

We have a history of losses and we expect losses to continue for at least the next three years.

As an exploration company that has no production history, we have incurred losses since our inception and we expect to continue to incur additional losses for at least the next three years. As of June 30, 2009, we had an accumulated deficit of approximately $39.9 million. There can be no assurance that we will achieve or sustain profitability in the future.

There are differences in U.S. and Canadian requirements for reporting of resources and mineralization, and some information required by Canadian reporting is not permitted under SEC guidelines.

The exploration of mineral properties is highly speculative in nature, involves substantial expenditures and is frequently non-productive.

Mineral exploration is highly speculative in nature and is frequently non-productive. Substantial expenditures are required to:

If we discover ore at the Montanore Project, we expect that it would be several additional years from the initial phases of exploration until production is possible. During this time, the economic

feasibility of production could change. As a result of these uncertainties, there can be no assurance that our exploration programs will result in new proven and probable reserves in sufficient quantities to justify commercial operations at the Montanore Project.

Even if our exploration efforts at Montanore are successful, we may not be able to raise the funds necessary to develop the Montanore Project.

If our exploration efforts at Montanore are successful, our current estimates indicate that we would be required to raise approximately $415 million in external financing to develop and construct the Montanore Project. Sources of external financing could include bank borrowings and debt and equity offerings, but financing has become significantly more difficult to obtain in the current market environment. The failure to obtain financing would have a material adverse effect on our growth strategy and our results of operations and financial condition. There can be no assurance that we will commence production at Montanore or generate sufficient revenues to meet our obligations as they become due or obtain necessary financing on acceptable terms, if at all, and we may not be able to secure the financing necessary to begin or sustain production at the Montanore Project. In addition, should we incur significant losses in future periods, we may be unable to continue as a going concern, and we may not be able to realize our assets and settle our liabilities in the normal course of business at amounts reflected in our financial statements included or incorporated by reference in this prospectus.

We may not be able to obtain permits required for development of the Montanore Project.

In the ordinary course of business, mining companies are required to seek governmental permits for expansion of existing operations or for the commencement of new operations. We will be required to obtain numerous permits for our Montanore Project. Obtaining the necessary governmental permits is a complex and time-consuming process involving numerous jurisdictions and often involving public hearings and costly undertakings. Obtaining required permits for the Montanore Project may be more difficult due to its location within the Cabinet Wilderness Area, its proximity to core habitat of certain protected species, including the grizzly bear, bull trout and lynx, and the efforts of a third party to permit another mining operation near the Montanore Project. Private groups dedicated to protection of the environment have been active in opposing permitting of other projects in and near the Cabinet Wilderness Area.

In addition, mining projects require the evaluation of environmental impacts for air, water, vegetation, wildlife, cultural, historical, geological, geotechnical, geochemical, soil and socioeconomic conditions. An Environmental Impact Statement would be required before we could commence mine development or mining activities. Baseline environmental conditions are the basis on which direct and indirect impacts of the Montanore Project are evaluated and based on which potential mitigation measures would be proposed. If the Montanore Project were found to significantly adversely impact the baseline conditions, we could incur significant additional costs to avoid or mitigate the adverse impact, and delays in the Montanore Project could result.

become such that we would not proceed with the further exploration, development or operation of a mine or mines at the Montanore Project.

The mining industry is intensely competitive. We may be at a competitive disadvantage because we must compete with other individuals and companies, many of which have greater financial resources, operational experience and technical capabilities than we do. Increased competition could adversely affect our ability to attract necessary capital funding or acquire suitable producing properties or prospects for mineral exploration in the future. We may also encounter increasing competition from other mining companies in our efforts to locate acquisition targets, hire experienced mining professionals and acquire exploration resources.

Our future mining operations, if any, would be subject to all of the hazards and risks normally incident to developing and operating mining properties. These risks include:

Our future profitability will be affected by changes in the prices of metals.

The aggregate effect of these factors on metals prices is impossible for us to predict. Decreases in metals prices could adversely affect our ability to finance the exploration and development of our properties, which would have a material adverse effect on our financial condition and results of operations and cash flows. There can be no assurance that metals prices will not decline. As reported on the website www.kitco.com, during the five-year period ended September 30, 2009, the high and low settlement prices for silver were $20.92 and $6.39 per ounce. As reported on the website www.tradeservice.com, the high and low settlement prices for copper were $4.07 and $1.24 per pound during the five-year period ended September 30, 2009.

We have ongoing reclamation obligations on the Montanore Project properties.

Our operations and exploration and development activities are subject to extensive federal, state, and local laws and regulations governing various matters, including:

Changes in mining or environmental laws could increase costs and impair our ability to develop our properties.

Mining exploration and mining are subject to the potential risks and liabilities associated with pollution of the environment and the disposal of waste products occurring as a result of mineral exploration and production. Insurance against environmental risk (including potential liability for pollution or other hazards as a result of the disposal of waste products occurring from exploration and production) is not generally available to us (or to other companies in the minerals industry) at a reasonable price. To the extent that we become subject to environmental liabilities, the satisfaction of those liabilities would reduce funds otherwise available to us and could have a material adverse effect

on us. Laws and regulations intended to ensure the protection of the environment are constantly changing, and are generally becoming more restrictive.

Although the Montanore deposit is held by patented mining claims, a significant portion of our holdings consist of unpatented lode and millsite claims. Certain of our United States mineral rights consist of "unpatented" mining and millsite claims created and maintained in accordance with the U.S. General Mining Law of 1872, which we refer to in this prospectus as the General Mining Law. Unpatented mining and millsite claims are unique U.S. property interests, and are generally considered to be subject to greater title risk than other real property interests because the validity of unpatented mining and millsite claims is often uncertain. This uncertainty arises, in part, out of the complex federal and state laws and regulations that supplement the General Mining Law. Also, unpatented mining and millsite claims and related rights, including rights to use the surface, are subject to possible challenges by third parties or contests by the federal government. The validity of an unpatented mining or millsite claim, in terms of both its location and its maintenance, is dependent on strict compliance with a complex body of federal and state statutory and decisional law. In addition, there are few public records that definitively control the issues of validity and ownership of unpatented mining and millsite claims. We have not filed a patent application for any of our unpatented mining and millsite claims that are located on federal public lands in the United States and, under possible future legislation to change the General Mining Law, patents may be difficult to obtain.

In recent years, the U.S. Congress has considered a number of proposed amendments to the General Mining Law, as well as legislation that would make comprehensive changes to the law. Although no such legislation has been adopted to date, there can be no assurance that such legislation will not be adopted in the future. If adopted, such legislation could, among other things, impose royalties on silver and copper production from unpatented mining and millsite claims located on federal lands or impose fees on production from patented mining and millsite claims. Further, it could have an adverse impact on earnings from our operations, could reduce estimates of any reserves we may establish and could curtail our future exploration and development activity on federal lands or patented claims.

While we have no reason to believe that title to any of our properties is in doubt, title to mining properties is subject to potential claims by third parties claiming an interest in them.

Certain provisions of our articles of incorporation, as amended, our bylaws, as amended, and of Idaho law could discourage, delay or prevent a merger, acquisition, or other change of control that shareholders may consider favorable, including transactions in which you might otherwise receive a premium for your shares of common stock of our company. Specifically, our articles of incorporation divides our board of directors into three classes having staggered terms of office. This may prevent or frustrate attempts by our shareholders to replace or remove our management. We have also implemented a shareholders rights plan, also called a poison pill, which would substantially reduce or eliminate the expected economic benefit to an acquirer from acquiring us in a manner or on terms not approved by our board of directors. These and other impediments to a third party acquisition or change of control could limit the price investors are willing to pay in the future for shares of our common stock. Our board of directors has also approved employment agreements with certain of our executive officers that include change of control provisions that provide severance benefits in the event that their employment terminates involuntarily without cause or for good reason within twelve months after a change of control of us. These agreements could affect the consummation of and the terms of a

third party acquisition. We are also subject to provisions of Idaho law that could have the effect of delaying, deferring or preventing a change in control of our company. One of these provisions prevents us from engaging in a business combination with any interested shareholder for a period of three years from the date the person becomes an interested shareholder, unless specified conditions are satisfied.

Our management could have broad discretion over the use of the net proceeds from any particular offering, and you will not necessarily know how the proceeds are to be used. You may not agree with how we use the proceeds and the proceeds may not be invested successfully.

As described under the heading "Use of Proceeds" below and in any prospectus supplement, we may use the net proceeds from particular offerings for a number of general corporate purposes, including, among other things, our drilling program at the Montanore Project and funding of acquisitions. Therefore, particularly with respect to the portion of proceeds allocated to acquisitions and general corporate purposes, our management will have broad discretion as to the use of the offering proceeds. Accordingly, you will be relying on the judgment of our management with regard to the use of these net proceeds, and you will not have the opportunity to approve any particular acquisition or to assess whether the proceeds are being used in a manner of which you approve. It is possible that the proceeds will be invested in ways that do not yield a favorable, or any, return for us.

The market price of our common stock is subject to volatility and could decline significantly.

Our common stock is listed on the NYSE Amex and the Toronto Stock Exchange, or TSX. Securities of small-cap companies such as ours have experienced substantial volatility in the past, often based on factors unrelated to the financial performance or prospects of the companies involved. These factors include macroeconomic developments in North America and globally and market perceptions of the attractiveness of particular industries. This volatility has been exacerbated in the latter half of 2008 and the first half of 2009 because of global economic disruptions. Our share price is also likely to be significantly affected by short-term changes in silver and copper prices or in our financial condition or results of operations as reflected in our quarterly earnings reports. Over the last three years, the closing price of our common shares as reported on the NYSE Amex has fluctuated from a low of $0.57 per share to a high of $6.44 per share. Other factors unrelated to our performance that could have an effect on the price of our common stock include the following:

Our shareholders are subject to future dilution by the exercise of options and warrants, and the existence of a significant number of options and warrants can depress the price of our common stock.

As of September 30, 2009, we had 22,920,076 shares outstanding. As of that date, there were (i) options outstanding to purchase up to 1,710,000 shares of common stock at exercise prices ranging from $0.99 to $5.70 per share and (ii) warrants outstanding to purchase 5,300,784 shares at exercise prices ranging from $4.00 to $5.75 per share. We have customarily repriced stock options when the exercise price falls $1.00 or more below the prevailing market price of our common stock. 2,565,000 additional shares of common stock are available for issuance under our stock option plans. If we issue additional options or warrants, or if currently outstanding options or warrants to purchase our common stock are exercised, the investments of our shareholders would be further diluted. In addition, the potential for exercise of a significant number of options and warrants can have a depressive effect on the market price for our common stock.

Unless otherwise indicated in the applicable prospectus supplement, we intend to use the net proceeds from the sale of the securities offered under this prospectus to advance the development drilling program at the Montanore Project, for the acquisition, exploration and development of additional companies, properties or interests, for working capital and for general corporate purposes. Pending the application of the net proceeds, we expect to invest the proceeds in treasury bills, investment-grade, interest-bearing instruments, or other securities.

We may sell the securities offered by means of this prospectus and any related prospectus supplement directly to one or more purchasers, through agents, or through underwriters or dealers designated from time to time. We may distribute such securities from time to time in one or more transactions at a fixed price or prices (which may be changed from time to time), at market prices prevailing at the times of sale, at prices related to these prevailing market prices or at negotiated prices. We may offer securities in the same offering, or we may offer securities in separate offerings. The applicable prospectus supplement will describe the terms of the offering of our securities, including:

If underwriters are used in the sale, the securities will be acquired by the underwriters for their own account and may be resold from time to time in one or more transactions, including negotiated transactions, at a fixed public offering price or at varying prices determined at the time of sale. The securities may be either offered to the public through underwriting syndicates represented by managing underwriters or by underwriters without a syndicate. The obligations of the underwriters to purchase securities will be subject to the conditions precedent agreed to by the parties and the underwriters will be obligated to purchase all the securities of a class or series if any are purchased. Any initial public offering price and any discounts or concessions allowed or reallowed or paid to dealers may be changed from time to time.

During and after an offering through underwriters, the underwriters may purchase and sell the securities in the open market. These transactions may include stabilizing transactions, over-allotment transactions, syndicate covering transactions and penalty bids in accordance with Regulation M under the Exchange Act. These stabilizing transactions, over-allotment transactions, syndicate covering transactions and penalty bids may have the effect of raising or maintaining the market price of the offered securities or preventing or retarding a decline in the market price of the offered securities. As a result, the price of the offered securities may be higher than the price that might otherwise exist in the open market. These transactions may be effected on the NYSE Amex, Toronto Stock Exchange or otherwise and, if commenced, may be discontinued at any time.

Securities may be sold directly by us or through agents or underwriters designated by us from time to time. We may authorize agents or underwriters to solicit offers by eligible institutions to purchase securities from us at the public offering price set forth in the prospectus supplement under delayed delivery contracts providing for payment and delivery on a specified date in the future. The conditions to these contracts and any underwriting compensation paid by us to underwriters or agents in connection with the offering of securities offered by means of this prospectus, and any discounts, concessions or commissions allowed by underwriters to participating dealers, will be set forth in the applicable prospectus supplement. Underwriters, dealers and agents participating in the distribution of the offered securities may be deemed to be underwriters, and any discounts or commissions received by them and any profit realized by them upon the resale of the offered securities may be deemed to be underwriting discounts and commissions, under the Securities Act.

Agents and underwriters may be entitled to indemnification by us against some civil liabilities, including liabilities under the Securities Act, or to contribution with respect to payments which the agents or underwriters may be required to make relating to these liabilities. Agents and underwriters may be customers of, engage in transactions with, or perform services for, us in the ordinary course of business.

In addition, any securities covered by this prospectus that qualify for sale pursuant to Rule 144 or Rule 144A under the Securities Act, may be sold under Rule 144 or Rule 144A rather than pursuant to this prospectus.

Each class or series of securities other than the common stock will be a new issue of securities with no established trading market. Any underwriter may make a market in these securities, but will not be obligated to do so and may discontinue any market making at any time without notice. No assurance can be given as to the liquidity of the trading market for any securities.

With respect to the sale of any securities under this prospectus, the maximum commission or discount to be received by any member of the Financial Industry Regulatory Authority, Inc. or independent broker or dealer will not be greater than eight percent (8%).

We are authorized to issue 100,000,000 shares of common stock, par value $0.001 per share. As of September 30, 2009, there were 22,920,076 shares of common stock issued and outstanding and 9,575,784 shares of common stock reserved for issuance under our stock option plans and associated with outstanding stock options and outstanding warrants.

Holders of our common stock may receive dividends when, as and if declared by our board on the common stock, subject to the preferential dividend rights of any other classes or series of shares of our company. In no event may a dividend be declared or paid on the common stock if payment of the dividend would cause the realizable value of our assets to be less than the aggregate of our liabilities and the amount required to redeem all of the shares having redemption or retraction rights that are then outstanding.

Holders of our common stock are entitled to one vote per share, and in general, all matters will be determined by a majority of votes cast, other than the election of directors as discussed below. Holders of our common stock are not entitled to pre-emptive rights.

Our board of directors is elected to staggered terms, with each class of directors standing for election every three years. Directors are elected by a plurality of the votes cast by the holders of our common stock in a meeting at which a quorum is present. "Plurality" means that the individuals who receive the largest number of votes cast are elected as directors, up to the maximum number of directors to be chosen at the meeting.

In the event of any liquidation, dissolution or winding up of Mines Management, holders of our common stock have the right to a ratable portion of the assets remaining after payment of liabilities and liquidation preferences of any preferred stock or other securities that may then be outstanding.

All outstanding shares of our common stock are, and the shares offered by this prospectus or obtainable on exercise or conversion of other securities offered hereby, if issued in the manner described in this prospectus and the applicable prospectus supplement will be, fully paid and nonassessable.

You should read the prospectus supplement relating to any offering of common stock, or of securities convertible, exchangeable or exercisable for common stock, for the terms of the offering, including the number of shares offered, the initial offering price and market prices relating to the shares.

This section is a summary and may not describe every aspect of our common stock that may be important to you. We urge you to read our articles of incorporation, and our bylaws because they, and

not this description, define your rights as a holder of our common stock. See "Where You Can Find More Information" for information on how to obtain copies of these documents.

Computershare Trust Company, N.A. in Denver, Colorado is the transfer agent and registrar for our common stock.

All shares of our common stock are issued with preferred share purchase rights attached thereto. On June 18, 2009, our board of directors declared a dividend distribution of one preferred share purchase right for each outstanding share of our common stock. Each right entitles the registered holder to purchase from us one one-thousandth of a share of Series A Junior Participating Preferred Stock at a purchase price of $12.00 in cash, subject to adjustment, if and when the rights become exercisable. Each one-thousandth of a share of Series A Junior Participating Preferred Stock will give the holder approximately the same dividend, voting and liquidation rights as would one share of our common stock. Prior to exercise, the right does not give its holder any dividend, voting, or liquidation rights. The description and terms of the rights are set forth in a Rights Agreement, dated as of June 18, 2009, between us and Computershare Trust Company, N.A., as rights agent. The rights are not exercisable or detachable from the common stock until ten days after any person or group acquires 20% or more (or commences a tender offer for 20% or more) of our common stock. If any person or group acquires 20% or more of our common stock or acquires us in a merger or other business combination, each right (other than those held by the acquiring person or group) will entitle the holder to purchase our common stock or common stock of the acquiring company having a market value of approximately two times the $12.00 exercise price. The rights expire on June 18, 2019, and can be redeemed by us at any time prior to their becoming exercisable at a redemption price of $0.001 per right.

We are authorized to issue up to 10,000,000 shares of preferred stock, without par value. As of October 9, 2009, there were no shares of preferred stock outstanding. Preferred stock is issuable in such classes or series as are determined by the board of directors, who have the authority to determine the relative rights and preferences of each such class or series. The board of directors has not designated any class or series of preferred stock, except for 40,000 shares of Series A Junior Participating Preferred Stock which were designated in connection with our shareholder rights plan described above.

The issuance of preferred stock could adversely affect the voting power of holders of our common stock, and the likelihood that preferred holders will receive dividend and liquidation preferences may have the effect of delaying, deferring or preventing a change in control of Mines Management, which could depress the market price of our common stock. All preferred stock to be issued from time to time under this prospectus will be fully paid and nonassessable.

The prospectus supplement relating to any preferred stock offered will contain a description of the specific terms of that series as fixed by our board of directors, including, as applicable:

The applicable prospectus supplement will also contain a discussion of the material United States federal income tax considerations relevant to the purchase and ownership of the preferred stock offered by the prospectus supplement.

The transfer agent for each series of preferred stock will be described in the prospectus supplement.

As of September 30, 2009, there were three series of warrants outstanding to purchase a total of 5,300,784 shares of common stock as follows:

Issued with:		Date Issued		Exercise Price		Term	Expiration Date

Equity offering		February 3, 2004 and February 13. 2004	362,250	$	4.00	6 years	February 10, 2010
Equity offering		October 20, 2005	1,520,234	$	4.00	5 years	October 20, 2010
Equity offering		April 20, 2007	3,418,300	$	5.75	5 years	April 20, 2012
	Total	—	5,300,784		—	—	—

We may issue warrants for the purchase of debt securities, preferred stock, common stock or units consisting of any combination of the foregoing securities. Each series of warrants will be issued under a separate warrant agreement. The applicable prospectus supplement will describe the terms of the warrants offered, including but not limited to the following:

Prior to the exercise of any warrants, holders of such warrants will not have any rights of holders of the securities purchasable upon such exercise, including the right to receive payments of dividends, or the right to vote such underlying securities.

Prospective purchasers of warrants should be aware that special United States federal income tax, accounting and other considerations may be applicable to instruments such as warrants. The applicable prospectus supplement will describe such considerations, to the extent they are material, as they apply generally to purchasers of such warrants.

This prospectus describes certain general terms and provisions of our debt securities and convertible debt securities that we may offer from time to time. When we offer to sell a particular series of debt securities or convertible debt securities, we will describe the specific terms of the series in a supplement to this prospectus. If there are any differences between the applicable prospectus supplement and this prospectus, the applicable prospectus supplement will control. As a result, the statements we make in this section may not apply to the debt security or convertible debt security that you purchase. As of the date of this prospectus, we have no outstanding registered debt securities.

The debt securities will be issued under an indenture between us and a duly qualified financial institution, as trustee. Any such indenture entered into by us will be governed by the Trust Indenture Act. Unless otherwise specified in a supplement to this prospectus, the debt securities or convertible debt securities will be our direct, senior unsecured obligations and will rank equally with all of our other senior unsecured indebtedness. We have summarized select portions of the indenture below. The summary may not contain all the terms that are important to you. You should read the form of the indenture that has been filed as an exhibit to the registration statement of which this prospectus is a part. Capitalized terms used in the summary have the meanings specified in the indenture.

The terms of each series of debt securities or convertible debt securities will be established by or pursuant to a resolution of our board of directors and set forth or determined in the manner provided in an officer's certificate or by a supplemental indenture. The particular terms of each series of debt securities or convertible debt securities will be described in a prospectus supplement relating to such series.

The indenture does not limit the amount of debt securities or convertible debt securities that we may issue under the indenture. The debt securities or convertible debt securities may be issued in one or more series with the same or various maturities, at par, at a premium, or at a discount. We will set forth in a prospectus supplement relating to any series of debt securities or convertible debt securities

being offered the aggregate principal amount, prices and terms of the securities. These terms may include:

We may issue debt securities or convertible debt securities that provide for an amount less than their stated principal amount to be due and payable upon declaration of acceleration of their maturity pursuant to the terms of the indenture.

If we denominate the purchase price of any of the debt securities or convertible debt securities in a foreign currency or currencies or a foreign currency unit or units, or if the principal of and any premium and interest on any series of debt securities or convertible debt securities is payable in a foreign currency or currencies or a foreign currency unit or units, we will provide you with information on the restrictions, elections, general tax considerations, specific terms and other information with respect to that issue of debt securities or convertible debt securities and such foreign currency or currencies or foreign currency unit or units in the applicable prospectus supplement.

Each debt security or convertible debt security will be represented by either one or more global securities registered in the name of The Depository Trust Company, as depositary, or a nominee (we refer to any debt security or convertible debt security represented by a global debt security as a "book-entry debt security"), or a certificate issued in definitive registered form (we refer to any debt security represented by a certificated security as a "certificated debt security") as set forth in the applicable prospectus supplement. Except as set forth under the heading "Book-Entry Debt Securities" below, debt securities will not be issuable in certificated form.

Each global debt security representing book-entry debt securities will be deposited with, or on behalf of, the depositary, and registered in the name of the depositary or a nominee of the depositary. The depositary has indicated it intends to follow the following procedures with respect to book-entry debt securities.

Ownership of beneficial interests in book-entry debt securities will be limited to persons that have accounts with the depositary for the related global debt security, which we refer to as participants, or persons that may hold interests through participants. Upon the issuance of a global debt security, the depositary will credit, on its book-entry registration and transfer system, the participants' accounts with the respective principal amounts of the book-entry debt securities represented by such global debt security beneficially owned by such participants. The accounts to be credited will be designated by any dealers, underwriters or agents participating in the distribution of the book-entry debt securities. Ownership of book-entry debt securities will be shown on, and the transfer of such ownership interests will be effected only through, records maintained by the depositary for the related global debt security (with respect to interests of participants) and on the records of participants (with respect to interests of persons holding through participants). The laws of some states may require that certain purchasers of securities take physical delivery of such securities in definitive form. These laws may impair the ability to own, transfer or pledge beneficial interests in book-entry debt securities.

So long as the depositary for a global debt security, or its nominee, is the registered owner of that global debt security, the depositary or its nominee, as the case may be, will be considered the sole owner or holder of the book-entry debt securities represented by such global debt security for all purposes under the indenture. Except as described below, beneficial owners of book-entry debt securities will not be entitled to have securities registered in their names, will not receive or be entitled to receive physical delivery of a certificate in definitive form representing securities and will not be considered the owners or holders of those securities under the indenture. Accordingly, each person beneficially owning book-entry debt securities must rely on the procedures of the depositary for the related global debt security and, if such person is not a participant, on the procedures of the participant through which such person owns its interest, to exercise any rights of a holder under the indenture.

We understand, however, that under existing industry practice, the depositary will authorize the persons on whose behalf it holds a global debt security to exercise certain rights of holders of debt securities, and the indenture provides that we, the trustee and our respective agents will treat as the holder of a debt security the persons specified in a written statement of the depositary with respect to that global debt security for purposes of obtaining any consents or directions required to be given by holders of the debt securities pursuant to the indenture.

We will make payments of principal of, and premium and interest on, book-entry debt securities to the depositary or its nominee, as the case may be, as the registered holder of the related global debt security. Mines Management, the trustee and any other agent of ours or agent of the trustee will not have any responsibility or liability for any aspect of the records relating to or payments made on account of beneficial ownership interests in a global debt security or for maintaining, supervising or reviewing any records relating to beneficial ownership interests.

We expect that the depositary, upon receipt of any payment of principal of, or premium or interest on, a global debt security, will immediately credit participants' accounts with payments in amounts proportionate to the respective amounts of book-entry debt securities held by each participant as shown on the records of such depositary. We also expect that payments by participants to owners of beneficial interests in book-entry debt securities held through those participants will be governed by standing customer instructions and customary practices, as is now the case with the securities held for the accounts of customers in bearer form or registered in "street name," and will be the responsibility of those participants.

We will issue certificated debt securities in exchange for each global debt security if the depositary is at any time unwilling or unable to continue as depositary or ceases to be a clearing agency registered under the Exchange Act, and a successor depositary registered as a clearing agency under the Exchange Act is not appointed by us within 90 days. In addition, we may at any time and in our sole discretion determine not to have the book-entry debt securities of any series represented by one or more global debt securities and, in that event, will issue certificated debt securities in exchange for the global debt securities of that series. Global debt securities will also be exchangeable by the holders for certificated debt securities if an event of default with respect to the book-entry debt securities represented by those global debt securities has occurred and is continuing. Any certificated debt securities issued in exchange for a global debt security will be registered in such name or names as the depositary shall instruct the trustee. We expect that such instructions will be based upon directions received by the depositary from participants with respect to ownership of book-entry debt securities relating to such global debt security.

We have obtained the foregoing information concerning the depositary and the depositary's book-entry system from sources we believe to be reliable, but we take no responsibility for the accuracy of this information.

You may transfer or exchange certificated debt securities at any office we maintain for this purpose in accordance with the terms of the indenture. No service charge will be made for any transfer or exchange of certificated debt securities, but we may require payment of a sum sufficient to cover any tax or other governmental charge payable in connection with a transfer or exchange.

You may effect the transfer of certificated debt securities and the right to receive the principal of, premium and interest on certificated debt securities only by surrendering the certificate representing those certificated debt securities and either reissuance by us or the trustee of the certificate to the new holder or the issuance by us or the trustee of a new certificate to the new holder.

Unless we state otherwise in the applicable prospectus supplement, the debt securities will not contain any provisions which may afford holders of the debt securities protection in the event we have a change in control or in the event of a highly leveraged transaction (whether or not such transaction results in a change in control) which could adversely affect holders of debt securities.

We will set forth in the applicable prospectus supplement any restrictive covenants applicable to any issue of debt securities. Unless otherwise provided in the applicable prospectus supplement, the following covenant will apply to all debt securities.

Consolidation, Merger and Sale of Assets. We may not, unless the terms of debt securities provide otherwise, consolidate with or merge with or into, or convey, transfer or lease all or substantially all of our properties and assets to, any person, which we refer to as a successor person, unless:

Unless otherwise provided in the applicable prospectus supplement, the indenture defines an event of default with respect to any series of debt securities, as one or more of the following:

No event of default with respect to a particular series of debt securities (except as to certain events of bankruptcy, insolvency or reorganization) necessarily constitutes an event of default with respect to any other series of debt securities. The occurrence of an event of default may constitute an event of default under other indebtedness in existence from time to time, including bank debt, if any. In addition, the occurrence of certain events of default or an acceleration under the indenture may constitute an event of default under certain of our other indebtedness outstanding from time to time.

If an event of default with respect to debt securities of any series at the time outstanding occurs and is continuing, then the trustee or the holders of not less than 50% in principal amount of the outstanding debt securities of that series may, by a notice in writing to us (and to the trustee if given by the holders), declare to be due and payable immediately the principal (or, if the debt securities of that series are discount securities, that portion of the principal amount as may be specified in the terms of that series) of and accrued and unpaid interest, if any, on all debt securities of that series. In the case of an event of default resulting from certain events of bankruptcy, insolvency or reorganization, the principal (or such lesser amount) of and accrued and unpaid interest, if any, on all outstanding debt securities will become and be immediately due and payable without any declaration or other act on the part of the trustee or any holder of outstanding debt securities. At any time after a declaration of acceleration with respect to debt securities of any series has been made, but before a judgment or decree for payment of the money due has been obtained by the trustee, the holders of a majority in

principal amount of the outstanding debt securities of that series may rescind the acceleration if all events of default, other than the non-payment of accelerated principal and interest, if any, with respect to debt securities of that series, have been cured or waived as provided in the indenture. We refer you to the prospectus supplement relating to any series of debt securities that are discount securities for the particular provisions relating to acceleration of a portion of the principal amount of such discount securities upon the occurrence of an event of default.

Subject to certain rights of the trustee, the holders of a majority in principal amount of the outstanding debt securities of any series will have the right to direct the time, method and place of conducting any proceeding for any remedy available to the trustee or exercising any trust or power conferred on the trustee with respect to the debt securities of that series. The indenture provides that the trustee will be under no obligation to exercise any of its rights or powers under the indenture at the request of any holder of outstanding debt securities if the request conflicts with law or the indenture, is unduly prejudicial to the rights of another holder of debt securities of that series, or may involve the trustee in personal liability.

No holder of any debt security of any series will have any right to institute any proceeding, judicial or otherwise, with respect to the indenture or for the appointment of a receiver or trustee, or for any remedy under the indenture, unless:

Notwithstanding the foregoing, the holder of any debt security's right to receive payment of the principal of, premium and any interest on that debt security on or after the due dates expressed in that debt security and to institute suit for the enforcement of payment shall not be impaired or affected without the consent of the holder.

The indenture requires us, within 120 days after the end of our fiscal year, to furnish to the trustee a statement as to compliance with the indenture. The indenture provides that the trustee may withhold notice to the holders of debt securities of any series of any default or event of default (except in payment on any debt securities of that series) with respect to debt securities of that series if it in good faith determines that withholding notice is in the interest of the holders of those debt securities.

Mines Management and the trustee as to any series of debt securities may modify and amend the indenture with the consent of the holders of at least a majority in principal amount of the outstanding debt securities of each series affected by the modifications or amendments. The holders of at least a majority in principal amount of outstanding debt securities of the series affected may also waive compliance in a particular instance with any provision of the indenture. Nevertheless, in no event may a modification, amendment or waiver, without the consent of each holder of each series of affected debt security then outstanding:

Subject to the limitations discussed above, the holders of a majority in principal amount of the outstanding debt securities of any series may on behalf of the holders of all the debt securities of such series waive any existing or past default or event of default under the indenture with respect to that series and its consequences, except a default or event of default in the payment of the principal of, premium or any interest on any debt security of that series or in respect of a covenant or provision which cannot be modified or amended without the consent of the holder of each outstanding debt security of the series affected; provided, however, that the holders of a majority in principal amount of the outstanding debt securities of any series may rescind an acceleration and its consequences, including any related payment default that resulted from the acceleration.

Defeasance of Debt Securities and Certain Covenants in Certain Circumstances

Legal Defeasance. The indenture provides that, unless otherwise provided by the terms of the applicable series of debt securities, we may be discharged from any and all obligations in respect of the debt securities of any series (except for certain obligations to register the transfer or exchange of debt securities of such series, to replace stolen, lost or mutilated debt securities of such series, and to maintain paying agencies and certain provisions relating to the treatment of funds held by paying agents). We will be so discharged upon the deposit with the trustee, in trust, of money and/or United States government obligations or, in the case of debt securities denominated in a single currency other than United States dollars, foreign government obligations, that, through the payment of interest and principal in accordance with their terms, will provide money in an amount sufficient in the opinion of a nationally recognized firm of independent public accountants to pay and discharge each installment of principal, premium and interest on and any mandatory sinking fund payments in respect of the debt securities of that series on the stated maturity of those payments in accordance with the terms of the indenture and those debt securities.

This discharge may occur only if, among other things, we have delivered to the trustee an opinion of counsel to the effect that the holders of the debt securities of that series will not recognize income, gain or loss for United States federal income tax purposes as a result of the deposit, defeasance and discharge and will be subject to United States federal income tax on the same amounts and in the same manner and at the same times as would have been the case if the deposit, defeasance and discharge had not occurred.

Covenant Defeasance. The indenture provides that, unless otherwise provided by the terms of the applicable series of debt securities, upon compliance with certain conditions:

Covenant Defeasance and Events of Default. In the event we exercise our option to effect covenant defeasance with respect to any series of debt securities, and the debt securities of that series are declared due and payable because of the occurrence of any event of default, the amount of money and/or United States government obligations or foreign government obligations on deposit with the trustee will be sufficient to pay amounts due on the debt securities of that series at the time of their stated maturity but may not be sufficient to pay amounts due on the debt securities of that series at the time of the acceleration resulting from the event of default. However, we shall remain liable for those payments.

For purposes of this discussion, "foreign government obligations" means, with respect to debt securities of any series that are denominated in a currency other than United States dollars:

We will provide you with information on the federal income tax and other special considerations applicable to any of these debt securities in the applicable prospectus supplement.

We may issue rights to our shareholders for the purchase of debt securities, preferred stock, or common stock. These rights may be issued independently or together with any other security offered hereby and may or may not be transferable by the shareholder receiving the rights in such offering. In connection with any offering of such rights, we may enter into a standby arrangement with one or more underwriters or other purchasers pursuant to which the underwriters or other purchasers may be required to purchase any securities remaining unsubscribed for after such offering.

Each series of rights will be issued under a separate rights agreement which we will enter into with a bank or trust company, as rights agent, all as set forth in the applicable prospectus supplement. The rights agent will act solely as our agent in connection with the certificates relating to the rights and will not assume any obligation or relationship of agency or trust with any holders of rights certificates or beneficial owners of rights. We will file the rights agreement and the rights certificates relating to each series of rights with the SEC, and incorporate them by reference as an exhibit to the registration statement of which this prospectus is a part on or before the time we issue a series of rights.

The applicable prospectus supplement will describe the specific terms of any offering of rights for which this prospectus is being delivered, including the following:

The description in the applicable prospectus supplement of any rights that we may offer will not necessarily be complete and will be qualified in its entirety by reference to the applicable rights certificate, which will be filed with the SEC.

As specified in the applicable prospectus supplement, we may issue units consisting of one or more debt securities, shares of common stock or preferred stock, warrants or any combination of such securities. In addition, the prospectus supplement relating to units will describe the terms of any units we issue, including as applicable:

The validity of the securities offered by this prospectus will be passed upon by Davis Graham & Stubbs LLP, Denver, Colorado.

Our audited consolidated financial statements as of December 31, 2007 and for the years ended December 31, 2007 and 2006, included in our Annual Report on Form 10-K for the year ended December 31, 2008 have been audited by LeMaster & Daniels PLLC, an independent registered public accounting firm. Our audited consolidated financial statements as of and for the year ended December 31, 2008, included in our Annual Report on Form 10-K for the year ended December 31, 2008, have been audited by the independent registered public accounting firm Tanner LC. Each of our audited consolidated financial statements are incorporated herein by reference to the extent and for the period set forth in and in reliance upon the reports given on the authority of LeMaster & Daniels PLLC and Tanner LC as experts in accounting and auditing.

Our mineralized material, or mineral resources, at December 31, 2008, incorporated by reference herein, was calculated by Mine Development Associates Inc. All such information incorporated by reference herein is presented in reliance upon the authority of that firm as experts in such matters.

You should rely only on the information incorporated by reference or provided in this prospectus or any supplement to this prospectus. We have authorized no one to provide you with different information. We are not making an offer of these securities in any state where the offer is not permitted. You should not assume that the information in this prospectus is accurate as of any date other than the date on the front of this prospectus.


Preliminary Prospectus Supplement		Filed Pursuant to Rule No. 424(b)(5)
To Prospectus dated October 27, 2009		Registration No. 333-162555

	Per Share	Total

Public offering price	$	$
Underwriting discount	$	$
Proceeds before expenses, to us	$	$

		Page

Prospectus Supplement
ABOUT THIS PROSPECTUS SUPPLEMENT		S-1
WHERE TO FIND ADDITIONAL INFORMATION		S-1
CAUTIONARY NOTE REGARDING FORWARD-LOOKING STATEMENTS		S-2
INCORPORATION OF CERTAIN INFORMATION BY REFERENCE		S-4
SUMMARY		S-5
THE OFFERING		S-7
RISK FACTORS		S-9
THE COMPANY		S-20
USE OF PROCEEDS		S-25
CONSOLIDATED CAPITALIZATION		S-26
PRICE RANGE OF OUR COMMON STOCK		S-27
DESCRIPTION OF COMMON STOCK		S-27
UNDERWRITING		S-28
MATERIAL U.S. FEDERAL INCOME TAX CONSIDERATIONS		S-32
LEGAL MATTERS		S-36
INTEREST OF EXPERTS		S-36
Base Prospectus
ABOUT THIS PROSPECTUS		1
WHERE YOU CAN FIND MORE INFORMATION		1
INCORPORATION OF CERTAIN INFORMATION BY REFERENCE		2
CAUTIONARY NOTE TO UNITED STATES INVESTORS CONCERNING ESTIMATES OF MEASURED, INDICATED AND INFERRED RESOURCES		3
RATIO OF EARNINGS TO FIXED CHARGES		3
FORWARD-LOOKING STATEMENTS		3
OUR BUSINESS		5
RISK FACTORS		8
USE OF PROCEEDS		15
PLAN OF DISTRIBUTION		15
DESCRIPTION OF COMMON STOCK		17

		Page

DESCRIPTION OF PREFERRED STOCK		18
DESCRIPTION OF WARRANTS		19
DESCRIPTION OF CONVERTIBLE DEBT SECURITIES AND DEBT SECURITIES		20
DESCRIPTION OF RIGHTS		28
DESCRIPTION OF UNITS		29
LEGAL MATTERS		29
EXPERTS		29

		Tons			Silver Grade (Ounces per ton)			Copper Grade			Cutoff Grade (Silver ounces per ton)

Mineralized Material			81,506,000			2.04			0.75	%		1.0


Transfer Agent		The transfer agent for our common stock is Computershare Trust Company, N.A. in Denver, Colorado.


Montanore Project		$
Acquisition and exploration of new precious metals projects, properties or companies		$
General corporate purposes		$

TOTAL		$

	Without Option	With Option

Per Share	$	$
Total	$	$