MCEWEN MINING INC.
(Exact name of registrant as specified in its charter)
SEE TABLE OF ADDITIONAL REGISTRANTS

181 Bay Street, Bay Wellington Tower, Suite 4750
P.O.Box 792
Toronto, ON
Canada M5J 2T3
(866) 441-0690
(Address, including zip code, and telephone number, including area code, of registrant's principal executive offices)

Corporate Secretary
McEwen Mining Inc.
181 Bay Street, Bay Wellington Tower, Suite 4750
P.O.Box 792
Toronto, ON
Canada M5J 2T3
(866) 441-0690
(Name, address, including zip code, and telephone number, including area code, of agent for service)

George A. Hagerty, Esq.
Hogan Lovells US LLP
One Tabor Center, Suite 1500
1200 Seventeenth Street
Denver, CO 80202
(303) 899-7300

Approximate date of commencement of proposed sale to the public: From time to time after this registration statement becomes effective.

If the only securities being registered on this Form are being offered pursuant to dividend or interest reinvestment plans, please check the following box. o

If any of the securities being registered on this Form are to be offered on a delayed or continuous basis pursuant to Rule 415 under the Securities Act of 1933, other than securities offered only in connection with dividend or interest reinvestment plans, check the following box. ý

If this Form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, please check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering. o

If this Form is a post-effective amendment filed pursuant to Rule 462(c) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering. o

If this Form is a registration statement pursuant to General Instruction I.D. or a post-effective amendment thereto that shall become effective upon filing with the Commission pursuant to Rule 462(e) under the Securities Act, check the following box. o

If this Form is a post-effective amendment to a registration statement filed pursuant to General Instruction I.D. filed to register additional securities or additional classes of securities pursuant to Rule 413(b) under the Securities Act, check the following box. o

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, or a smaller reporting company. See the definitions of "large accelerated filer," "accelerated filer," and "smaller reporting company" in Rule 12b-2 of the Exchange Act.

Title of each class of securities to be registered(1)	Amount to be registered(2)	Proposed maximum offering price per unit(2)(3)	Proposed maximum aggregate offering price(1)	Amount of registration fee(1)(2)




Debt Securities	(4)	(4)

Guarantees of the Co-Registrants of the Debt Securities(5)	(4)	(5)

Common Stock, no par value per share	(4)	(4)

Warrants(6)	(4)	(4)

Subscription Rights	(4)	(4)

Subscription Receipts(7)	(4)	(4)

Total			$200,000,000(8)	$21,380(9)(10)

The Registrant hereby amends this Registration Statement on such date or dates as may be necessary to delay its effective date until the Registrant shall file a further amendment which specifically states that this Registration Statement shall thereafter become effective in accordance with Section 8(a) of the Securities Act of 1933 or until the Registration Statement shall become effective on such date as the Commission, acting pursuant to said Section 8(a), may determine.

Exact Name of Registrant as Specified in its Charter	State of Incorporation or Organization

US Gold Canadian Acquisition Corporation(1)	Alberta, Canada	42-1701924
Nevada Pacific Gold Ltd.(2)	British Columbia, Canada	—
Tone Resources Limited(2)	British Columbia, Canada	55-0790533
White Knight Resources Ltd.(2)	British Columbia, Canada	—
US Gold Alberta ULC(1)	Alberta, Canada	98-0555049
Tonkin Springs Gold Mining Company(3)	Colorado	84-0988517
Tonkin Springs Venture Limited Partnership(4)	Nevada	88-0267851
Tonkin Springs LLC(5)	Delaware	84-1493124
U.S. Environmental Corporation(3)	Colorado	84-1216116
McEwen Mining—Minera Andes Acquisition Corp.(6)	Alberta, Canada	—
McEwen Mining (Alberta) ULC(7)	Alberta, Canada	—
Minera Andes Inc.(8)	Alberta, Canada	—

(1): The address and telephone number of such co-registrant's principal executive offices is 181 Bay Street, Bay Wellington Tower, Suite 4750, Toronto, ON Canada M5J 2T3, (866) 441-0690, and the address and telephone number of such co-registrant's agent for service is Fraser Milner Casgrain LLP, 2900 Manulife Place, 10180-101 Street, Edmonton, Alberta, Canada T5J 3V5, (780) 423-7100.
(2): The address and telephone number of such co-registrant's principal executive offices is 181 Bay Street, Bay Wellington Tower, Suite 4750, Toronto, ON Canada M5J 2T3, (866) 441-0690, and the address and telephone number of such co-registrant's agent for service is Fraser Milner Casgrain LLP, 20th Floor, 250 Howe Street, Vancouver, B.C., V6C 3R8, (604) 687-4460.
(3): The address and telephone number of such co-registrant's principal executive offices is 181 Bay Street, Bay Wellington Tower, Suite 4750, Toronto, ON Canada M5J 2T3, (866) 441-0690, and the address and telephone number of such co-registrant's agent for service is David J. Babiarz, 1700 Broadway, Suite 2100, Denver, CO 80290, (303) 861-8013.
(4): The address and telephone number of such co-registrant's principal executive offices is 181 Bay Street, Bay Wellington Tower, Suite 4750, Toronto, ON Canada M5J 2T3, (866) 441-0690, and the address and telephone number for such co-registrant's agent for service is Thomas P. Erwin, P.O. Box 40817, One E. Liberty, Suite 424, Reno, NV 89504, (775) 786-9494.
(5): The address and telephone number of such co-registrant's principal executive offices is 181 Bay Street, Bay Wellington Tower, Suite 4750, Toronto, ON Canada M5J 2T3, (647) 258-0395, and the address and telephone number for such co-registrant's agent for service is Corporation Service Company, 2711 Centerville Road, Suite 400, Wilmington, DE 19808, (302) 636-5401.
(6): The address and telephone number of such co-registrant's principal executive offices is 181 Bay Street, Bay Wellington Tower, Suite 4750, Toronto, ON Canada M5J 2T3, (866) 441-0690, and the address and telephone number for such co-registrant's agent for service is Colleen Cebuliak, Fraser Milner Casgrain LLP, 2900 Manulife Place, 10180-101 Street, Edmonton, Alberta T5J 3V5 (780) 423-7136.
(7): The address and telephone number of such co-registrant's principal executive offices is 181 Bay Street, Bay Wellington Tower, Suite 4750, Toronto, ON Canada M5J 2T3, (866) 441-0690, and the address and telephone number for such co-registrant's agent for service is Colleen Cebuliak, Fraser Milner Casgrain LLP, 2900 Manulife Place, 10180-101 Street, Edmonton, Alberta T5J 3V5 (780) 423-7136.
(8): The address and telephone number of such co-registrant's principal executive offices is 181 Bay Street, Bay Wellington Tower, Suite 4750, Toronto, ON Canada M5J 2T3, (866) 441-0690, and the address and telephone number for such co-registrant's agent for service is Lawson Lundell LLP, Suite 3700-205, 5 Avenue SW, Calgary, Alberta T2P 2V7.

The information in this prospectus is not complete and may be changed. We may not sell these securities until the registration statement filed with the Securities and Exchange Commission is effective. This prospectus is not an offer to sell these securities and it is not soliciting an offer to buy these securities in any state where the offer or sale is not permitted.

Debt Securities (which may be guaranteed by one or more of our Co-Registrants)
Common Stock
Warrants
Subscription Rights
Subscription Receipts

This prospectus relates to the issuance, offer and sale from time to time by McEwen Mining Inc. of: debt securities (which may be guaranteed by one or more of our Co-Registrants); common stock; warrants to purchase debt securities or common stock, which we refer to as debt warrants and warrants, respectively; subscription rights to purchase shares of common stock, debt warrants, warrants or other securities; and subscription receipts that may be exchanged for debt securities, common stock, debt warrants or warrants. We refer to our debt securities (which may be guaranteed by one or more of our Co-Registrants), common stock, debt warrants, warrants, subscription rights and subscription receipts collectively as the securities.

This prospectus describes some of the general terms that may apply to the securities we may issue or offer. Each time that securities are offered and sold or issued by us using this prospectus, we will provide a supplement to this prospectus that contains specific information about the offering or issuance. The supplement also may add or update information contained in this prospectus. You should read this prospectus, any post-effective amendment and any prospectus supplement carefully before you invest.

The securities may be offered and sold or issued by us to or through one or more underwriters, dealers or agents or directly to purchasers on a continuous or delayed basis. See "Plan of Distribution" beginning on page 30 of this prospectus.

Our common stock is listed on the New York Stock Exchange under the symbol "MUX." Our common stock as more fully described beginning on page 32 of this prospectus, is also listed on the Toronto Stock Exchange under the symbol "MUX". Our exchangeable shares issued in 2012, as more fully described beginning on page 33, are listed on the Toronto Stock Exchange under the symbol "MAQ".

Investing in our securities involves risks. For a discussion of risk factors that you should consider in investing in our securities, see the section entitled "Risk Factors," beginning on page 2 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.

This prospectus is part of a registration statement that we filed with the Securities and Exchange Commission ("SEC"), utilizing a "shelf" registration process. Under this process, McEwen Mining Inc., US Gold Canadian Acquisition Corporation ("2007 Exchange Co."), Nevada Pacific Gold Ltd. ("Nevada Pacific"), Tone Resources Limited ("Tone"), White Knight Resources Ltd. ("White Knight"), US Gold Alberta ULC ("US Gold Alberta"), Tonkin Springs Gold Mining Company ("Tonkin Springs Gold"), Tonkin Springs Venture Limited Partnership ("Tonkin Springs Venture"), Tonkin Springs LLC ("Tonkin Springs LLC"), U.S. Environmental Corporation ("US Environmental"), McEwen Mining—Minera Andes Acquisition Corp. ("Canadian Exchange Co.") and McEwen Mining (Alberta) ULC ("Callco"), and Minera Andes Inc. ("Minera Andes") (which we generally refer to collectively as "we", "us", "McEwen Mining" or the "Company" in this prospectus, as applicable, and 2007 Exchange Co., Canadian Exchange Co., Callco, Minera Andes, Nevada Pacific, Tone, White Knight, US Gold Alberta, Tonkin Springs Gold, Tonkin Springs Venture, Tonkin Springs LLC, and U.S. Environmental may be referred to each as a "Co-Registrant" and collectively as "Co-Registrants," as applicable) may, from time to time, offer, sell and issue any of the securities or any combination of the securities described in this prospectus in one or more offerings up to a total dollar amount of $200,000,000. This prospectus provides you with a general description of the securities we may offer, sell or issue. Each time we offer securities, we will provide a prospectus supplement and attach it to this prospectus. The prospectus supplement will contain specific information about the terms of the securities being offered, sold or issued at that time. The prospectus supplement may also add, update or change information contained in this prospectus. You should read both this prospectus, any post-effective amendment, any prospectus supplement, and any information incorporated by reference into the prospectus, any post-effective amendment, and prospectus supplement, together with the information described under the headings, "Where to Find Additional Information" and "Incorporation of Certain Information by Reference" and any additional information you may need to make your investment decision.

This prospectus incorporates documents containing important business and financial information about the Company by reference that are not presented or delivered with this prospectus. Copies of these documents are available without charge, upon written or oral request by a person to whom this prospectus has been delivered. Requests should be made to: McEwen Mining Inc., at 181 Bay Street, Bay Wellington Tower, Suite 4750, Toronto, ON Canada M5J 2T3, (866) 441-0690. To ensure timely delivery of the documents, requests should be made no later than five business days prior to the date on which a final investment decision is to be made.

Readers should rely only on the information provided or incorporated by reference in this prospectus, any post-effective amendment, or any prospectus supplement. Readers should not assume that the information in this prospectus, any post-effective amendment, or any prospectus supplement is accurate as of any date other than the date on the front cover of the document. We have not authorized anyone to provide you with different information. We are not making an offer of these securities in any state where the offer is not permitted.

Unless otherwise stated, currency amounts in this prospectus are stated in U.S. dollars, or "$".

McEwen Mining is engaged in the exploration for and production of precious metals in the U.S., Mexico and Argentina. We were organized under the laws of the State of Colorado on July 24, 1979 under the name Silver State Mining Corporation. On June 21, 1988, we changed our name to U.S. Gold Corporation and on March 16, 2007, we changed our name to US Gold Corporation. On January 24, 2012, we changed our name to McEwen Mining Inc.

Our objective is to increase the value of our shares through the exploration, development, and extraction of gold, silver and other valuable minerals. Other than the Company's San José Mine in Argentina, we generally conduct our exploration activities as sole operator, but we may enter into arrangements with other companies through joint venture or similar agreements in an effort to achieve our strategic objectives. We own our mineral interests and property and operate our business through various subsidiary companies, each of which is owned entirely, directly, or indirectly, by us.

In June 2007, we completed three simultaneous acquisitions, significantly increasing our land position in Nevada and Mexico. The assets of these three companies, Nevada Pacific, Tone and White Knight (the "2007 Acquired Companies"), included a portfolio of properties in Nevada and Mexico. As a result of these acquisitions, we now hold interests in approximately 254 square miles in Nevada, and approximately 1,631 square miles of mineral concessions in west central Mexico. In 2011, we began efforts to place one of our Mexican properties into production with mining expected to commence at the end of the second quarter of 2012, and are taking steps to place one of our Nevada properties into production.

On January 24, 2012, we completed the acquisition of Minera Andes by way of a court-approved plan of arrangement under the Business Corporations Act (Alberta).

We presently hold an interest in numerous exploration and development stage properties and projects in Mexico, Nevada and Argentina, as well as a 49% equity interest in the gold-silver San José Mine in Santa Cruz Province, Argentina. Prior to the acquisition of Minera Andes, we had not generated revenue from operations since 1990. As a result of the acquisition of Minera Andes, we expect to generate revenue in 2012 from our 49% interest in the San José Mine.

We hold interests in approximately 1,631 square miles of mineral concessions in west central Mexico. Our primary property in Mexico is the El Gallo Complex, located in Sinaloa state on the Sierra Madre Trend, a geological area of significant gold and silver mineralization. In 2010, we completed two estimates of mineralized material on the El Gallo Complex and in February 2011, we completed an NI 43-101 Compliant Preliminary Economic Assessment of that Complex. On August 31, 2011, we announced the commencement of work towards the first phase of production on the El Gallo Complex and we intend to complete a Technical Report that will evaluate production coming from the Phase 2 area at the El Gallo Complex by approximately the middle of 2012.

We hold interests in approximately 254 square miles in Nevada, United States. The majority of our Nevada properties, including our interests in our Gold Bar project and the Tonkin Complex, are located along the Cortez Trend, in north central Nevada. We also own property, including our Limo project, on the southern end of the Carlin Trend. Both the Cortez Trend and Carlin Trend are geological areas of significant gold discoveries. In 2006, we commenced comprehensive exploration of our Tonkin property in an effort to identify additional mineralized material. From 2008 through 2009, we drilled various targets on our Gold Bar and Limo projects, as well as expanded the quantity of estimated mineralized material at our Gold Bar project in updated technical reports. In 2010, we completed a Preliminary Economic Assessment for our Gold Bar project and in 2011 completed a pre-feasibility study under NI 43-101 on the project. The Company has decided to place the property into production, subject to receipt of necessary permits.

Effective January 24, 2012, we acquired Minera Andes and in turn acquired: a 49% interest in Minera Santa Cruz SA, owner of the San José Silver-Gold Mine in Santa Cruz, Argentina; a 100% interest in the Los Azules Copper Deposit in San Juan, Argentina, and a large portfolio of exploration properties in Santa Cruz, Argentina. The San José Mine is operated by the majority owner of the joint venture, Hochschild Mining plc. We currently hold mineral rights and applications for mineral rights covering approximately 944 square miles in Argentina.

Our principal executive office is located at 181 Bay Street, Bay Wellington Tower, Suite 4750, Toronto, ON Canada M5J 2T3 and our telephone number is (866) 441-0690. We also maintain offices in San Juan (Argentina), Guamuchil (Mexico), and Elko and Reno. Our website is www.mcewenmining.com. We make available our periodic reports and press releases on our website. Our common stock is listed on the New York Stock Exchange ("NYSE") and on the Toronto Stock Exchange ("TSX"), in each case, under the symbol "MUX". Shares of Canadian Exchange Co. which are exchangeable on a one-for-one basis into McEwen Mining common stock and which were issued in connection with our acquisition of Minera Andes, are listed on the TSX under the symbol "MAQ". Except for documents that are incorporated by reference into this prospectus, any post-effective amendment, or any prospectus supplement that may be accessed from our web site, the information available on or through our web site is not part of this prospectus.

An investment in our securities involves a high degree of risk. You should consider carefully the following risk factors, along with all of the other information contained in or incorporated by reference in this prospectus, any post-effective amendment, and any applicable prospectus supplement, before deciding to buy our securities. 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 market price of our securities. 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 market price of our securities could be materially and adversely affected.

We have incurred substantial losses since our inception in 1979 and may never be profitable. Since our inception in 1979, we have never been profitable and we have not generated revenue from operations since 1990. As of March 31, 2012, our accumulated deficit was approximately $412 million, including certain non-cash expenses. Over the longer term, our ability to become profitable will depend on the profitability of the San José Mine, our ability to bring the El Gallo Complex and our Gold Bar project into production and generate revenue sufficient to cover our costs and expenses, and our ability to advance or sell our other properties, including the Los Azules copper project. We will seek to identify additional mineralization that can be extracted economically at operating and exploration properties. For our non-operating properties that we believe demonstrate economic potential, we need to either develop our properties, locate and enter into agreements with third party operators, or sell the properties. We may suffer significant additional losses in the future and may never be profitable. Even if we do achieve profitability, we may not be able to sustain or increase profitability on a quarterly or annual basis.

The feasibility of mining at our El Gallo Complex and Gold Bar properties, has not been established in accordance with SEC Guide 7, and any funds spent by us on exploration and development could be lost. We have no proven or probable reserves on our properties as defined by U.S. law. A "reserve," as defined by regulation of the SEC, is that part of a mineral deposit which could be economically and legally extracted or produced at the time of the reserve determination. A reserve requires a feasibility study demonstrating with reasonable certainty that the deposit can be economically extracted and produced.

As a result, we currently have no reserves defined by SEC Guide 7 and there are no assurances that we will be able to prove that there are reserves on our properties.

The mineralized material identified on our properties does not and may never demonstrate economic viability. Substantial expenditures are required to establish reserves through drilling and additional study and there is no assurance that reserves will be established. The feasibility of mining on our El Gallo Complex, Gold Bar properties, or any other property has not been, and may never be, established. Whether a mineral deposit can be commercially viable depends upon a number of factors, including the particular attributes of the deposit, including size, grade and proximity to infrastructure; metal prices, which can be highly variable; and government regulations, including environmental and reclamation obligations. If we are unable to establish some or all of our mineralized material as proven or probable reserves in sufficient quantities to justify commercial operations, our investment in that property will be lost, and the market value of our securities may suffer.

We are required to prepare and file with the Canadian securities regulators estimates of mineralized material in accordance with the National Instrument 43-101—Standards of Disclosure for Mineral Projects of the Canadian Securities Administrators ("NI 43-101"). These standards are substantially different from the standards generally permitted to report reserve and other estimates in reports and other materials filed with 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. U.S. investors are cautioned not to assume that all or any part of measured or indicated resources reported in our Canadian filings will ever be converted into SEC Guide 7 compliant reserves.

The figures for our estimated mineralized material are based on interpretation and assumptions and may yield less mineral production under actual conditions than is currently estimated. Unless otherwise indicated, mineralization figures presented in our filings with securities regulatory authorities including the SEC, press releases and other public statements that may be made from time to time are based upon estimates made by independent geologists and our internal geologists. When making determinations about whether to advance any of our projects to development, we must rely upon such estimated calculations as to the mineralized material and grades of mineralization on our properties. Until ore is actually mined and processed, mineralized material and grades of mineralization must be considered as estimates only.

These estimates are imprecise and depend upon geological interpretation and statistical inferences drawn from drilling and sampling analysis, which may prove to be unreliable. We cannot assure you that:

Any material changes in mineral estimates and grades of mineralization will affect the economic viability of placing a property into production and such property's return on capital. There can be no assurance that minerals recovered in small scale tests will be recovered in large-scale tests under on-site conditions or in production scale.

The estimates contained in our public filings have been determined and valued based on assumed future prices, cut-off grades and operating costs that may prove to be inaccurate. Extended declines in market prices for gold and/or silver may render portions of our mineralization estimates uneconomic and result in reduced reported mineralization or adversely affect the commercial viability of one or more of our properties. Any material reductions in estimates of mineralization, or of our ability to extract this mineralization, could have a material adverse effect on our results of operations or financial condition.

Our estimated timetables to achieve production for Phase 2 of the El Gallo Complex and our Gold Bar properties may not be accurate. Based on technical work recently completed, including the EL Gallo preliminary economic assessment and the Gold Bar preliminary feasibility study, we believe we can achieve Phase 2 production at the El Gallo Complex in 2014 and at our Gold Bar properties in 2015. However, the El Gallo preliminary economic assessment and the Gold Bar preliminary feasibility study are preliminary in nature and are subject to change due to factors within and outside of our control. We have not completed a feasibility study with regard to these or any of our properties and the feasibility of mining at these properties may never be established. There is no certainty that the preliminary assessment and economics estimated in those reports will be realized or that we will be able to begin production within the timelines estimated, if at all.

We will require significant amounts of capital through debt or equity to place one or more of our properties into production, and our ability to obtain this necessary funding will depend on a number of factors, including the status of the national and worldwide economy and the price of silver, gold, and other precious and base metals. Fluctuations in production costs, material changes in the mineral estimates and grades of mineralization or changes in the political conditions or regulations in Mexico or Nevada may make placing these properties into production uneconomic. Further, we may also be unable to obtain the necessary permits in a timely manner, on reasonable terms or on terms that provide us sufficient resources to develop our properties. These and other factors may cause us to delay Phase 2 production at the El Gallo Complex and our Gold Bar properties beyond 2014 and 2015, if at all or indefinitely.

Historical production of gold at our Tonkin Complex or Magistral Mine is not indicative of the potential for future development or revenue. Historical production of gold from our Tonkin Complex came from relatively shallow deposits, in very limited quantities and for a very limited period of time. Processing the mineralization at Tonkin also presents significant metallurgical difficulties that may cause it to be uneconomic or unfeasible to mine and process ore on a commercial scale. In Mexico, the Magistral Mine produced gold from 2002 through 2005, but it was shut down in 2006 and was held by us on a care and maintenance basis until the fourth quarter of 2011. The restart of the Magistral Mine is now considered Phase 1 of our El Gallo Complex; we made the decision to proceed with Phase 1 construction without the benefit of a feasibility study. There are significant risks and uncertainty associated with commencing production without a feasibility or pre-feasibility study. The area proposed for Phase 1 of El Gallo production has not been explored, developed and analyzed in sufficient detail to complete an independent feasibility or pre-feasibility study and may ultimately be determined to lack one or more geological, engineering, legal, operating, economic, social, environmental, and other relevant factors reasonably required to serve as the basis for a final decision to complete the development of all or part of the El Gallo project for mineral production. Investors in our securities should be cautioned not to rely on our historical operations as an indication that we will place those mining properties into commercial production or that any such attempts to resume production would be successful.

We will require significant additional capital to continue our exploration and development activities, and if warranted, to develop additional mining operations. As a result of the acquisition of Minera Andes, as well as the other properties that we own, substantial expenditures will be required to continue the exploration programs at its exploration stage properties. We will be required to expend significant amounts of capital for drilling, geological and geochemical analysis, assaying, and, if warranted, feasibility studies with regard to the results of our exploration. We may need to obtain additional financing, either in the form of debt or equity financing, to fund such expenditures. We may not benefit from these investments if we are unable to identify commercially exploitable reserves. Furthermore, expenditures we made for Minera Andes' properties may reduce the availability of capital to pursue our exploration and development programs at El Gallo Complex. If we are successful in identifying commercially exploitable reserves, we will require significant additional capital to extract those reserves.

Our ability to obtain necessary funding, in turn, depends upon a number of factors, including the state of the economy and applicable commodity prices. We may not be successful in obtaining the required financing for these or other purposes on terms that are favorable to us or at all, in which case, our ability to continue operating would be adversely affected. Failure to obtain such additional financing could result in delay or indefinite postponement of further exploration or potential development and the possible partial or total loss of our interest in certain properties.

The integration of our most recent acquisition of Minera Andes will present significant challenges. The integration of our operations with Minera Andes and the consolidation of those operations will require the dedication of management resources, which may temporarily divert attention from the day-to-day business of the Company. The process of combining the organizations may cause an interruption of, or a loss of momentum in our other activities, which could have an adverse effect on the operating results of the combined company for an indeterminate period of time. The failure to successfully integrate Minera Andes, to retain key personnel and to successfully manage the challenges presented by the integration process may prevent us from achieving the anticipated benefits of the acquisition. If we fail to realize the anticipated benefits of the acquisition, our results of operations, financial condition and cash flows may be adversely affected.

Minera Andes' assets may be less valuable to us than expected. The value of Minera Andes to us, other than its interest in the San José Mine, is based in large part on the value of the Los Azules Copper Project and the ability to discover mineralized material on the other acquired exploration properties. The Los Azules Copper Project has only "inferred resources" and "indicated resources", based on NI 43-101 definitions. There can be no assurance that these mineral resources will be upgraded to mineral reserves or that if mineral deposits are discovered on the other exploration properties, that such mineral deposits can be commercially mined. Whether a mineral deposit can be commercially viable depends upon a number of factors, including the particular attributes of the deposit, including size, grade and proximity to infrastructure; metal prices, which can be highly volatile; and government regulations, including environmental and reclamation obligations. If we are unable to establish some or all of the mineralized material as proven or probable reserves in sufficient quantities to justify commercial operations, the market value of our securities may decline, and you may lose some or all of your investment.

Development at the Los Azules copper project presents development challenges that may negatively affect, if not completely negate, the feasibility of development of the property. The Los Azules property that we acquired with Minera Andes is located in a remote location that is accessed by 75 miles (120 kilometers) of unimproved dirt road with eight river crossings and two mountain passes both above 13,451 feet (4,100 meters). According to the technical report prepared for Minera Andes with an effective date of December 1, 2010, capital costs were estimated to be $2.8 billion initially and $3.73 billion over the life of the mine with an accuracy target of plus or minus 35%. These are historical calculations and capital costs calculated today may be substantially higher. In order for the Los Azules property to be economically feasible for development, the price of copper would have to be high enough to justify the high capital costs estimated for the project. There can be no assurance that these capital cost estimates are accurate; given the inflationary pressure in the mining industry and in Argentina in particular, these capital costs are likely to increase substantially. If the long term price of copper were to decrease significantly below the current price or capital cost estimates increase significantly, the Los Azules property may not be feasible for development, and we may have to write-off the asset. Furthermore, even if the development of the Los Azules property becomes economically feasible, we may not be able to raise sufficient capital to develop the property, may not receive the required permits or environmental approvals, may not be able to construct the necessary power and infrastructure assets and may not be able to attract qualified workers to build such a project, any of which could result in the delay of or indefinitely postpone development at the property. Such a result would have a material negative effect on our Company.

The Los Azules copper project is subject to ongoing legal proceedings with the potential that we may lose part of our interest in the project. We are currently subject to ongoing litigation regarding the Los Azules Copper Project. TNR Gold Corp ("TNR Gold") and its subsidiary, Solitario Argentina S.A. ("Solitario" and together with TNR Gold, "TNR"), claim, among other things, that certain properties that comprise the Los Azules Copper Project were not validly transferred to Minera Andes and therefore should be returned to TNR. In the alternative, TNR claims that even if Minera Andes validly owns the Los Azules Copper Project, TNR has a 25% back-in right to a substantial portion of the Los Azules project underlying known mineral resources that may be exercised to acquire a 25% interest in such part of the property. TNR has also claimed damages. We estimate that the Los Azules Copper Project represents approximately 56% of the total assets acquired, not counting liabilities assumed, in the acquisition of Minera Andes, based on our preliminary estimate of the fair value of all identifiable assets acquired and liabilities assumed.

We are not able to estimate the potential financial impact of this claim. If resolved adversely against the Company, this litigation could materially adversely affect the value of the Company by reducing or terminating our interest in a significant portion of the Los Azules Copper Project and our ability to develop the Los Azules Copper Project. Alternatively, we could be subject to a significant damages award. Such a result would have a significant negative impact on the value of the Company and could have a significant impact on our stock price.

We are subject to litigation risks in addition to the Los Azules litigation. All industries, including the mining industry, are subject to legal claims, with and without merit. Defense and settlement costs can be substantial, even with respect to claims that have no merit. Due to the inherent uncertainty of the litigation process, the resolution of any particular legal proceeding could have a material adverse effect on our financial position and results of operations.

We may acquire additional exploration stage properties and we may face negative reactions if reserves are not located on acquired properties. We have in the past and may in the future acquire additional exploration stage properties. There can be no assurance that we have or will be able to complete the acquisition of such properties at reasonable prices or on favorable terms and that reserves will be identified on any properties that we acquire. We may also experience negative reactions from the financial markets if we are unable to successfully complete acquisitions of additional properties or if reserves are not located on acquired properties. These factors may adversely affect the trading price of our common stock or our financial condition or results of operations.

Fluctuating precious metals and copper prices could negatively impact our business. The potential for profitability of our silver and gold mining operations and the value of our mining properties are directly related to the market price of silver, gold and copper. The price of silver, gold and copper may also have a significant influence on the market price of our common stock. The market price of gold and silver historically has fluctuated significantly and is affected by numerous factors beyond our control. These factors include supply and demand fundamentals, expectations with respect to the rate of inflation, the relative strength of the U.S. dollar and other currencies, interest rates, gold and silver sales and loans by central banks, forward sales by metal producers, accumulation and divestiture by exchange traded funds, global or regional political, economic or banking crises, and a number of other factors. The market price of silver is also affected by industrial demand. The selection of a property for exploration or development, the determination to construct a mine and place it into production, and the dedication of funds necessary to achieve such purposes are decisions that must be made long before the first revenues, if any, from production will be received. Price fluctuations between the time that such decisions are made and the commencement of production can have a material adverse effect on the economics of a mine.

The volatility in silver, gold and copper prices is illustrated by the following table, which sets forth, for the periods indicated, the average market prices in U.S. dollars per ounce of gold and silver, based on the daily London P.M. fix, and per pound of copper based on the LME Grade A copper settlement price.

Average Annual Market Price of Silver and Gold (per oz.) and Copper (per lb.)

The volatility of mineral prices represents a substantial risk which no amount of planning or technical expertise can fully eliminate. In the event gold and silver prices decline and remain low for prolonged periods of time, we might be unable to develop our properties, which may adversely affect our results of operations, financial performance and cash flows.

Our continuing reclamation obligations at the Tonkin Complex, El Gallo Complex and our other properties could require significant additional expenditures. We are responsible for the reclamation obligations related to disturbances located on all of our properties, including the Tonkin Complex. We have posted a bond in the amount of the estimated reclamation obligation at the Tonkin Complex. We submitted a mine closure plan to the Bureau of Land Management ("BLM") for the Tonkin Complex during the fourth quarter of 2010. Based on our estimate, the change in our bonding requirements was insignificant. Our closure plan is currently under review by the BLM. We have not posted a bond in Mexico relating to the El Gallo Complex, as none is required. There is a risk that any cash bond, even if increased based on the analysis and work performed to update the reclamation obligations, could be inadequate to cover the actual costs of reclamation when carried out. The satisfaction of bonding requirements and continuing reclamation obligations will require a significant amount of capital. There is a risk that we will be unable to fund these additional bonding requirements, and further, that the regulatory authorities may increase reclamation and bonding requirements to such a degree that it would not be commercially reasonable to continue exploration activities, which may adversely affect our results of operations, financial performance and cash flows.

Our ongoing operations and past mining activities are subject to environmental risks, which could expose us to significant liability and delay, suspension or termination of our operations. All phases of our operations are subject to U.S., Mexican and Argentine federal, state and local environmental regulation. These regulations mandate, among other things, the maintenance of air and water quality standards and land reclamation. They also set forth limitations on the generation, transportation, storage and disposal of solid and hazardous waste. Environmental legislation is evolving in a manner which will require stricter standards and enforcement, increased fines and penalties for non-compliance, more stringent environmental assessments of proposed projects, and a heightened degree of responsibility for us and our officers, directors and employees. Future changes in environmental regulation, if any, may adversely affect our operations, make our operations prohibitively expensive, or prohibit them altogether. Environmental hazards may exist on our properties that are unknown to us at the present and that have been caused by us, or previous owners or operators, or that may have occurred naturally. Mining properties from the companies we have acquired may cause us to be liable for remediating any damage that those companies may have caused. The liability could include response costs for removing or remediating the release and damage to natural resources, including ground water, as well as the payment of fines and penalties.

We have transferred our interest in several mining properties over past years, some of which are now being operated by third parties. Under applicable U.S. federal and state environmental laws, as prior owner of these properties, we may be liable for remediating any damage that we may have caused. The liability could include response costs for removing or remediating the release and damage to natural resources, including ground water, as well as the payment of fines and penalties.

Failure to comply with applicable environmental laws, regulations and permitting requirements may result in enforcement actions thereunder, including orders issued by regulatory or judicial authorities, causing operations to cease or be curtailed, and may include corrective measures requiring capital expenditures, installation of additional equipment, or remedial actions.

Due to an increased level of non-governmental organization activity targeting the mining industry, the potential for the government to delay the issuance of permits or impose new requirements or conditions upon mining operations may be increased. Any changes in government policies may be costly to comply with and may delay mining operations. Future changes in such laws and regulations, if any, may adversely affect our operations, make our operations prohibitively expensive, or prohibit them altogether. If our interests are materially adversely affected as a result of a violation of applicable laws, regulations, or permitting requirements or a change in applicable law or regulations, it would have a significant negative impact the value of the combined company and could have a significant impact on our stock price.

Our operations are subject to permitting requirements which could require us to delay, suspend or terminate our operations on our mining properties. Our operations, including ongoing exploration drilling programs, require permits from the state and federal governments, including permits for the use of water and for drilling wells for water. We may be unable to obtain these permits in a timely manner, on reasonable terms or on terms that provide us sufficient resources to develop our properties, or at all. Even if we are able to obtain such permits, the time required by the permitting process can be significant. If we cannot obtain or maintain the necessary permits, or if there is a delay in receiving these permits, our timetable and business plan for exploration of our properties will be adversely affected, which may in turn adversely affect our results of operations, financial condition, cash flows and market price of our securities.

Our operations in Mexico and Argentina are subject to changes in political conditions, regulations and crime. Our El Gallo Complex as well as certain other concessions, are located in Mexico and are subject to laws and regulations applied by Mexican federal, state, and local governments. As a result, our mining investments in Mexico are subject to the risks normally associated with the conduct of business in foreign countries. In the past, Mexico has been subject to political instability, changes and uncertainties which may cause changes to existing government regulations affecting mineral exploration and mining activities. Civil or political unrest or violence could disrupt our operations at any time. In recent years, there has been a marked increase in the level of violence and crime relating to drug cartels in Sinaloa state, where we operate, and in other regions of Mexico. This may disrupt our ability to carry out exploration and mining activities and affect the safety and security of our employees and contractors. Our exploration and mining activities may be adversely affected in varying degrees by changing government regulations relating to the mining industry or shifts in political conditions, including as a result of upcoming national elections, that could increase the costs related to our activities or maintaining our properties.

Our San José Mine as well as certain other concessions, are located in Argentina and are subject to laws and regulations applied by Argentinian federal, provincial, and local governments. As a result, our mining investments in Argentina are subject to the risks normally associated with the conduct of business in foreign countries. There are risks relating to an uncertain or unpredictable political and economic environment in Argentina. During an economic crisis in 2002 and 2003, Argentina defaulted on foreign debt repayments and on the repayment on a number of official loans to multinational organizations. In addition, the Argentinean government has renegotiated or defaulted on contractual arrangements.

In January 2008, the Argentinean government reassessed its policy and practice in respect of export duties and began levying export duties on mining companies operating in the country. Although this particular change did not affect the San José Mine as its fiscal stability agreement explicitly fixes

export duties at 5% for doré bars and 10% for concentrates, there can be no assurance that the Argentinean government will not unilaterally take other action which could have a material adverse effect on our projects in the country. In October 2011, the Argentinean government announced a decree requiring mining companies to repatriate mining revenues to Argentina and to convert those revenues into Argentine pesos prior to taking any further action with respect to such revenues, such as paying suppliers or distributing profits, either locally or out of the country. This decree has resulted in increased foreign exchange and bank transaction costs to the Company and increased the Company's exposure to potential devaluation of the Argentine peso should the San José Mine be forced to hold more currency in Argentine pesos compared to U.S. dollars. There also is the risk of political violence and increased social tension in Argentina as Argentina has experienced periods of civil unrest, crime and labor unrest. Certain political and economic events such as acts, or failures to act, by a government authority in Argentina, and acts of political violence in Argentina, could have a material adverse effect on our ability to operate in the country.

Changes, if any, in mining or investment policies or shifts in political attitude in any of the jurisdictions in which the Company operates may adversely affect the Company's operations or profitability. Operations may be affected in varying degrees by government regulations with respect to, but not limited to, restrictions on production, price controls, export controls, currency remittance, importation of parts and supplies, income and other taxes, expropriation of property, foreign investment, maintenance of claims, environmental legislation, land use, land claims of local people, water use and mine safety.

Title to mineral properties can be uncertain, and we are at risk of loss of ownership of one or more of our properties, in addition to the Los Azules Copper Project. Our ability to explore and operate our properties depends on the validity of our title to that property. Our U.S. mineral properties consist of leases of unpatented mining claims, as well as unpatented mining and millsite claims which we control directly. Unpatented mining claims provide only possessory title and their validity is often subject to contest by third parties or the federal government, which makes the validity of unpatented mining claims uncertain and generally more risky. Our Mexico concessions are granted by the Mexican government for a period of up to 50 years from the date of their recording in the Public Registry of Mining and are renewable for a further period of up to 50 years upon application within five years of expiration of such concession in accordance with the Mining Law and its Regulations. Failure to do so prior to expiration of the term of the exploration concession will result in termination of the concession. Under Argentinean Law, concessions are granted by provincial governments for unlimited periods of time, subject to a mining fee and the filing of a minimum investment plan and compliance with a one-off minimum investment in the concession equal to 300 times the relevant mining fee over a five year period. Failure to comply with these conditions may result in the termination of the concession. Uncertainties inherent in mineral properties relate to such things as the sufficiency of mineral discovery, proper posting and marking of boundaries, assessment work and possible conflicts with other claims not determinable from public record. We have not obtained title opinions covering our entire property, with the attendant risk that title to some claims, particularly title to undeveloped property, may be defective. There may be valid challenges to the title to our property which, if successful, could impair development and/or operations.

We remain at risk in that the mining claims may be forfeited either due to failure to comply with statutory requirements as to location and maintenance of the claims or challenges to whether a discovery of a valuable mineral exists on every claim.

Legislation has been proposed that would significantly and adversely affect the mining industry. Periodically, members of the U.S. Congress have introduced bills which would supplant or alter the provisions of the General Mining Law of 1872, which governs the unpatented claims that we control with respect to our U.S. properties. One such amendment has become law and has imposed a moratorium on the patenting of mining claims, which reduced the security of title provided by unpatented claims such as those on our U.S. properties. If additional legislation is enacted, it could substantially increase the cost of holding unpatented mining claims by requiring payment of royalties, and could significantly impair our ability to develop mineral estimates on unpatented mining claims. Such bills have proposed, among other things, to make permanent the patent moratorium, to impose a federal royalty on production from unpatented mining claims and to declare certain lands as unsuitable for mining. Although it is impossible to predict at this time what royalties may be imposed in the future, the imposition of such royalties could adversely affect the potential for development of such mining claims, and the economics of existing operating mines on federal unpatented mining claims. Passage of such legislation could adversely affect our business.

There is an election scheduled in Mexico in July 2012 and one of the leading parties, Partido Revolucionario Institucional ("PRI"), had previously introduced a 4% mining royalty on production. To date, the Mexican Congress has been silent on the royalty proposal. Various proposals have been made at the federal and provincial level in Argentina to establish or increase royalties and taxes on the mining sector.

Our lack of operating experience may cause us difficulty in managing our growth. Our management team, as a whole, has limited experience in developing and operating a mine. We are currently working towards developing our El Gallo Complex in Mexico, our Gold Bar properties in Nevada, and our Los Azules Copper Project in Argentina. If we are unable to successfully place these projects into production, our stock price may suffer and you may lose some or all of your investment. Our ability to manage the anticipated growth that we expect will accompany placing one or more of those properties into production will require us to improve and expand our management and our operational systems and controls. If our management is unable to manage growth effectively, our business and financial condition would be materially harmed. In addition, if rapid growth occurs, it may strain our operational, managerial and financial resources.

We cannot assure you that we will have an adequate supply of water to complete desired exploration or development of our mining properties. In accordance with the laws of the State of Nevada, we have obtained permits to drill the water wells that we currently use to service the Tonkin property and we plan to obtain all required permits for drilling water wells to serve other properties we may develop or acquire in the future. However, the amount of water that we are entitled to use from those wells must be determined by the appropriate regulatory authorities. A final determination of these rights is dependent in part on our ability to demonstrate a beneficial use for the amount of water that we intend to use. Unless we are successful in developing the property to a point where we can commence commercial production of gold or other precious metals, we may not be able to demonstrate such beneficial use. Accordingly, there is no assurance that we will have access to the amount of water needed to operate a mine at the property, which may prevent us from generating revenue, and which would adversely affect our financial condition and cash flows.

Our industry is highly competitive, attractive mineral lands are scarce, and we may not be able to obtain quality properties. We compete with many companies in the mining industry, including large, established mining companies with substantial capabilities, personnel and financial resources. There is a limited supply of desirable mineral lands available for claim staking, lease or acquisition in the U.S., Mexico, Argentina, and other areas where we may conduct exploration activities. We may be at a competitive disadvantage in acquiring mineral properties, since we compete with these individuals and companies, many of which have greater financial resources and larger technical staffs than we do. From

time to time, specific properties or areas which would otherwise be attractive to us for exploration or acquisition may be unavailable to us due to their previous acquisition by other companies or our lack of financial resources. Competition in the industry is not limited to the acquisition of mineral properties but also extends to the technical expertise to find, advance, and operate such properties; the labor to operate the properties; and the capital for the purpose of funding such properties. Many competitors not only explore for and mine precious metals, but conduct refining and marketing operations on a world-wide basis. Such competition may result in our Company being unable not only to acquire desired properties, but to recruit or retain qualified employees or to acquire the capital necessary to fund our operation and advance our properties. Our inability to compete with other companies for these resources would have a material adverse effect on our results of operation, financial condition and cash flows.

The nature of mineral exploration and production activities involves a high degree of risk and the possibility of uninsured losses that could materially and adversely affect our operations. Exploration for minerals is highly speculative and involves greater risk than many other businesses. Many exploration programs do not result in the discovery of mineralization, and any mineralization discovered may not be of sufficient quantity or quality to be profitably mined. Few properties that are explored are ultimately advanced to production. Our current exploration efforts, and future development and mining operations we conduct will be, subject to all of the operating hazards and risks normally incident to exploring for and developing mineral properties, such as, but not limited to:

Any of these risks can materially and adversely affect, among other things, the development of properties, production quantities and rates, costs and expenditures, potential revenues and production dates. We currently have no insurance to guard against any of these risks, except in very limited circumstances. If we determine that capitalized costs associated with any of our mineral interests are not likely to be recovered, we would incur a writedown of our investment in these interests. All of these factors may result in losses in relation to amounts spent which are not recoverable.

We do not insure against all risks to which we may be subject in our planned operations. While we currently maintain insurance to insure against general commercial liability claims and physical assets at the Tonkin and El Gallo Complex, we do not maintain insurance to cover all of the potential risks associated with our operations. Our other exploration projects have no existing infrastructure for which we insure. We may also be unable to obtain insurance to cover other risks at economically feasible premiums or at all. Insurance coverage may not continue to be available, or may not be adequate to cover liabilities. We might also become subject to liability for environmental, pollution or other hazards associated with mineral exploration and production which may not be insured against, which may exceed the limits of our insurance coverage or which we may elect not to insure against because of premium costs or other reasons. Losses from these events may cause us to incur significant costs that could materially adversely affect our financial condition and our ability to fund activities on our property. A significant loss could force us to reduce or terminate our operations.

We depend on a limited number of personnel and the loss of any of these individuals could adversely affect our business. Our company is dependent on key management, namely our Chairman and Chief Executive Officer, our Vice President and Chief Financial Officer, our Chief Operating Officer, our Senior Vice President and Vice President, Projects. Robert R. McEwen, our Chairman and Chief Executive Officer, is responsible for strategic direction and the oversight of our business. Perry Y. Ing, our Vice President and Chief Financial Officer, is responsible for our public reporting and administrative functions. William Faust (Chief Operating Officer), Ian Ball (Senior Vice President), Simon Quick (Vice President, Projects), and Andrew Elinesky (Vice President, Argentina), oversee project development in, Mexico, Nevada and Argentina, respectively. We rely heavily on these individuals for the conduct of our business. The loss of any of these officers would significantly and adversely affect our business. In that event, we would be forced to identify and retain an individual to replace the departed officer. We may not be able to replace one or more of these individuals on terms acceptable to us. We have no life insurance on the life of any officer.

Some of our directors may have conflicts of interest as a result of their involvement with other natural resource companies. Some of our directors are directors or officers of other natural resource or mining-related companies, or may be involved in related pursuits that could present conflicts of interest with their roles at our Company. These associations may give rise to conflicts of interest from time to time. In the event that any such conflict of interest arises, a director who has such a conflict is required to disclose the conflict to the other directors and may be required to abstain from voting on the matter.

We are subject to foreign currency risk. While we transact most of our business in U.S. dollars, some expenses, such as labor, operating supplies and capital assets are denominated in Canadian dollars, Mexican pesos or Argentine pesos. As a result, currency exchange fluctuations may impact our operating costs. The appreciation of non-U.S. dollar currencies against the U.S. dollar increases costs and the cost of purchasing capital assets in U.S. dollar terms in Canada, Mexico and Argentina, which can adversely impact our operating results and cash flows. Conversely, a depreciation of non-U.S. dollar currencies usually decreases operating costs and capital asset purchases in U.S. dollar terms in foreign countries.

The value of cash and cash equivalents denominated in foreign currencies also fluctuates with changes in currency exchange rates. Appreciation of non-U.S. dollar currencies results in a foreign currency gain on such investments and a depreciation in non-U.S. dollar currencies results in a loss. We have not utilized market risk sensitive instruments to manage our exposure to foreign currency exchange rates but may in the future actively manage our exposure to foreign currency exchange rate risk. We also hold a majority of our cash reserves in non-U.S. dollar currencies.

New Argentinean foreign exchange regulations may make it difficult to transfer funds in and out of Argentina, which could adversely affect our liquidity and operations. Argentina recently announced a decree requiring mining companies to repatriate mining revenues to Argentine currency before

distributing revenue either locally or overseas. Fluctuation in the value of the Argentine peso as a result of the repatriation requirement and the repatriation requirement may create inefficiencies in our ability to transfer its revenue from Argentina and result in substantial transaction costs. Further, there are additional transaction costs imposed by the central bank for transferring funds from and within Argentina. These restrictions and any additional restrictions on the ability to access the Argentinean foreign exchange market and transfer foreign currency in and out of Argentina could adversely affect our liquidity and operations in Argentina, and our ability to access such funds.

Global climate change is an international concern, and could impact our ability to conduct future operations. Global climate change is an international issue and receives an enormous amount of publicity. We would expect that the imposition of international treaties or U.S., Mexican or Argentine federal, state or local laws or regulations pertaining to mandatory reductions in energy consumption or emissions of greenhouse gasses could affect the feasibility of our mining projects and increase our operating costs.

The laws of the State of Colorado and our Articles of Incorporation may protect our directors from certain types of lawsuits. The laws of the State of Colorado provide that our directors will not be liable to us or our shareholders for monetary damages for all but certain types of conduct as directors of the Company. Our Articles of Incorporation permit us to indemnify our directors and officers against all damages incurred in connection with our business to the fullest extent provided or allowed by law. The exculpation provisions may have the effect of preventing shareholders from recovering damages against our directors caused by their negligence, poor judgment or other circumstances. The indemnification provisions may require us to use our limited assets to defend our directors and officers against claims, including claims arising out of their negligence, poor judgment, or other circumstances.

Gain recognized by non-U.S. holders and non-U.S. persons holding any interest in the Company other than solely as a creditor (including, for example, interests in the form of our convertible debt, if any) on the sale or other disposition of our securities may be subject to U.S. federal income tax. We believe that we currently are a "United States real property holding corporation" under section 897(c) of the Internal Revenue Code, or USRPHC, and that there is a substantial likelihood that we will continue to be a USRPHC in the future. Subject to certain exceptions, securities (other than securities that provide no interest in a corporation other than solely as a creditor) issued by a corporation that has been a USRPHC at any time during the preceding five years (or the non-U.S. holder's holding period for such securities, if shorter) are treated as U.S. real property interests, or USRPIs, and gain recognized by a non-U.S. holder on the sale or other disposition of a USRPI is subject to regular U.S. federal income tax, on a net basis at graduated rates, as if such gain were effectively connected with the conduct by such holder of a U.S. trade or business. If gain recognized by a non-U.S. holder from the sale or other disposition of our common stock or other securities is subject to regular net basis income tax under these rules, the transferee of such common stock or other securities may be required to deduct and withhold a tax equal to 10% of the gross amount paid to the non-U.S. holder with respect to the sale or other disposition, unless certain exceptions apply. Any tax withheld may be credited against the U.S. federal income tax owed by the non-U.S. holder for the year in which the sale or other disposition occurs.

The conversion of outstanding exchangeable shares, exercise of options and the future issuances of our common stock will dilute current shareholders and may reduce the market price of our common stock. As of June 13, 2012, we had outstanding exchangeable shares and options to purchase a total of 91,166,268 shares of our common stock, which if completely converted or exercised, would dilute existing shareholders' ownership by approximately 50%, assuming all exchangeable shares not held by us or our subsidiaries are exchanged for an equivalent amount of our common stock. Under certain

circumstances, our board of directors has the authority to authorize the offer and sale of additional securities without the vote of or notice to existing shareholders. We may issue equity in the future in connection with acquisitions, strategic transactions or for other purposes. Based on the need for additional capital to fund expected growth, it is likely that we will issue additional securities to provide such capital and that such additional issuances may involve a significant number of shares. Issuance of additional securities in the future will dilute the percentage interest of existing shareholders and may reduce the market price of our common stock and other securities.

Furthermore, the sale of a significant amount of common stock by any selling security holders, specifically Robert R. McEwen, our Chairman and Chief Executive Officer, may depress the price of our common stock. As a result, you may lose all or a portion of your investment.

A small number of existing shareholders own a significant portion of our common stock, which could limit your ability to influence the outcome of any shareholder vote. Our Chairman and Chief Executive Officer, Robert R. McEwen, beneficially owns approximately 25% of our common stock as of June 13, 2012 (assuming all exchangeable shares not held by McEwen Mining or our subsidiaries are exchanged for an equivalent amount of our common stock). Under our Articles of Incorporation and the laws of the State of Colorado, the vote of the holders of a majority of the shares voting at a meeting at which a quorum is present is generally required to approve most shareholder action. As a result, this individual will be able to significantly influence the outcome of shareholder votes for the foreseeable future, including votes concerning the election of directors, amendments to our Articles of Incorporation or proposed mergers, acquisitions or other significant corporate transactions.

Our stock price has historically been volatile, and as a result you could lose all or part of your investment. The market price of our common stock has fluctuated significantly and may decline in the future. The high and low sale prices of our common stock on the NYSE Amex, and the NYSE after November 2, 2010, were $3.53 and $0.90 for the fiscal year ended December 31, 2009, $8.17 and $2.02 for the fiscal year ended December 31, 2010, $9.87 and $2.93 for the fiscal year ended December 31, 2011, and $5.97 and $2.16 for the period beginning January 1, 2012 and ending June 13, 2012. The fluctuation of the market price of our common stock has been affected by many factors that are beyond our control, including: changes in the worldwide price for silver, gold and copper, results from our exploration or development efforts and the other risk factors discussed herein.

We have never paid a dividend on our common stock and we do not anticipate paying one in the foreseeable future. We have not paid a dividend on our common stock to date, and we do not expect to be in a position to pay dividends in the foreseeable future. Our initial earnings from the San José Mine, if any, will likely be retained to finance our growth. Any future dividends will depend upon any future earnings, our then-existing financial requirements and other factors, and will be at the discretion of our board of directors.

The sale of our common stock by existing securityholders may depress the market value of our securities due to the limited trading market which exists. Due to a number of factors, the trading volume in our common stock has historically been limited. Trading volume over the past twelve months averaged approximately 4,000,000 shares per day. As a result, the sale of a significant amount of common stock by any selling securityholders may depress the price of our common stock. As a result, you may lose all or a portion of your investment.

Our ability to generate the cash needed to service our debt obligations, if any, depends on certain factors beyond our control. The future success of our operations will, in large part, dictate our ability to make scheduled payments on, and satisfy our obligations under our debt, if any, including our debt securities. Our future operating performance will be affected by general economic, competitive, market, business and other conditions, many of which are beyond our control. To the extent we are not able to meet our debt obligations, we will be required to restructure or refinance them, seek additional equity financing or sell assets. We may not be able to restructure or refinance our debt, obtain additional financing or sell assets on satisfactory terms or at all.

An adverse rating of our debt securities may cause their trading price to fall. If a rating agency rates our debt securities, if any, it may assign them a low rating. Rating agencies also may lower ratings on our debt securities, if any, in the future. If rating agencies assign a lower-than-expected rating or reduce, or indicate that they may reduce, their ratings in the future, the trading price of our debt securities, if any, could significantly decline.

We cannot assure you that an active trading market will develop for the securities. There is currently no public market for any of our securities other than our common stock and exchangeable shares. We do not know if an active market will develop for our other securities, or if developed, whether such a market will continue. If an active market is not developed or maintained, the market price and the liquidity of our other securities may be adversely affected.

This prospectus, any prospectus supplement and the information and documents incorporated herein by reference contain or will contain certain references to future expectations and other forward-looking statements and information relating to us or to properties operated by others that are based on our beliefs and assumptions or those of management of the companies that operate properties in which we have interests, as well as information currently available to us. Such forward-looking statements include statements regarding projected production and reserves received from the operators of properties where we have interests. Additional written or oral forward-looking statements may be made by us from time to time in filings with the SEC or otherwise. Words such as "may," "could," "should," "would," "believe," "estimate," "expect," "anticipate," "plan," "forecast," "potential," "intend," "continue," "project" and variations of these words, comparable words and similar expressions generally indicate forward-looking statements, which speak only as of the date the statement is made. Such forward-looking statements are within the meaning of that term in Section 27A of the Securities Act of 1933 (as amended, the "Securities Act") and Section 21E of the Securities Exchange Act of 1934 (as amended the "Exchange Act"). Future events and actual results, performance, transactions or achievements, financial and otherwise, may differ materially from the results, performance, transactions or achievements expressed or implied by the forward-looking statements. Forward-looking statements inherently involve risks and uncertainties, some of which cannot be predicted or quantified. Do not unduly rely on forward-looking statements. Actual results may differ materially from those expressed or implied by these forward-looking statements. Factors that could cause actual results to differ materially from these forward-looking statements include, among others:

This list is not an exhaustive list of the factors that may affect any of our forward-looking statements. Other unknown or unpredictable factors also could have a material adverse effect on our business, results of operations, financial condition or prospects. You should read this prospectus, any post-effective amendment and any prospectus supplement completely and with the understanding that our actual future results may be materially different from what we expect.

Although we believe that the expectations reflected in the forward-looking statements are reasonable, we cannot guarantee future results, levels of activity, performance or achievements. These forward-looking statements involve risks, uncertainties and other factors that may cause our actual results in future periods to differ materially from forecasted results. We disclaim any obligation to publicly update or revise these forward-looking statements, whether as a result of new information, future events or otherwise, other than to reflect a material change in the information previously disclosed, as required by applicable law. You should review our subsequent reports filed from time to

time with the SEC on Forms 10-K, 10-Q and 8-K and any amendments thereto. We qualify all of our forward-looking statements by these cautionary statements. Readers are cautioned not to put undue reliance on forward-looking statements. Please carefully review and consider the various disclosures contained or incorporated by reference in this prospectus that attempt to advise interested parties of the risks and factors that may affect our business, results of operations, financial condition or prospects.

Unless we specify otherwise in a prospectus supplement, we intend to use the net proceeds from sales of securities by us for general corporate purposes. If net proceeds from a specific offering will be used to repay indebtedness, the applicable prospectus supplement will describe the relevant terms of the debt to be repaid.

We are engaged in the exploration for and production of precious metals in the U.S., Mexico and Argentina. Prior to the acquisition of Minera Andes, none of our properties generated revenue from operations since 1990, and, with the exception of the San José Mine, we have no current operating income or operating cash flow. Accordingly, earnings were not sufficient to cover fixed charges by $0.00 in the years ended December 31, 2007, 2008, 2009, 2010 and 2011. As of the date of this prospectus, we have not issued any preferred stock other than the one share of Series B Special Voting Preferred Stock, which has no preference as to dividends, as more fully described beginning on page 33 of this prospectus and one share of Series A Special Voting Preferred Stock that is no longer outstanding, as more fully described beginning on page 40 of this prospectus. We did not have any material amount of indebtedness for which interest payments were required during the years ended December 31, 2007, 2008, 2009, 2010 or 2011 and, therefore the amount by which earnings were inadequate to cover fixed charges was not material.

The following description, together with the additional information we include in any post-effective amendment and applicable prospectus supplement, summarizes the material terms and provisions of the debt securities (which may be guaranteed by one or more of our Co-Registrants) that we may offer under this prospectus. While the terms we have summarized below will apply generally to any future debt securities we may offer under this prospectus, we will describe the particular terms of any debt securities that we may offer in more detail in any applicable prospectus supplement. You should also read the indenture under which the debt securities are to be issued. The terms of any debt securities we offer under a prospectus supplement may differ from the terms we describe below. However, no prospectus supplement shall fundamentally change the terms that are set forth in this prospectus or offer a security that is not registered and described in this prospectus at the time of its effectiveness. As of the date of this prospectus, we have no outstanding registered debt securities.

To the extent that we issue debt securities, we will issue the senior debt securities under the indenture that we will enter into with the trustee named in the indenture. The debt securities that we may issue include senior debt securities, subordinated debt securities, convertible debt securities and exchangeable debt securities. The following is a summary of the material provisions of the indenture filed as an exhibit to the registration statement which includes this prospectus. This summary is not complete and is qualified in its entirety by reference to all provisions of the indenture applicable to a particular series of debt securities. We urge you to read the applicable prospectus supplements related to the debt securities that we may sell under this prospectus, as well as the indenture that contains the

terms of the debt securities. For each series of debt securities, the applicable prospectus supplement for the series may change and supplement the summary below.

The indenture does not limit the amount of debt securities that we may issue. It provides that we may issue debt securities up to the principal amount that we may authorize and they may be in any currency or currency unit that we may designate. Except for the limitations on consolidation, merger and sale of all or substantially all of our assets contained in the indenture, the terms of the indenture do not contain any covenants or other provisions designed to give holders of any debt securities protection against changes in our operations, financial condition or transactions involving us. For each series of debt securities, any restrictive covenants for those debt securities will be described in the applicable prospectus supplement for those debt securities.

We may issue the debt securities issued under the indenture as "discount securities," which means they may be sold at a discount below their stated principal amount. These debt securities, as well as other debt securities that are not issued at a discount, may, for United States federal income tax purposes, be treated as if they were issued with "original issue discount," or OID, because of interest payment and other characteristics. Special United States federal income tax considerations applicable to debt securities issued with original issue discount will be described in more detail in any applicable prospectus supplement.

We will describe in each applicable prospectus supplement the terms relating to a series of debt securities, including:

We will set forth in the applicable prospectus supplement the terms on which a series of debt securities may be convertible into or exchangeable for our ordinary shares or our other securities. The terms will include, among others, the following:

The terms of the indenture prevent us from consolidating or merging with or into, or conveying, transferring or leasing all or substantially all of our assets to, any person, unless (i) we are the surviving corporation or the successor corporation or person to which our assets are conveyed, transferred or leased is organized under the laws of the United States, any state of the United States or the District of Columbia and it expressly assumes our obligations under the debt securities and the indenture and (ii) immediately after completing such a transaction, no event of default under the indenture, and no event that, after notice or lapse of time or both, would become an event of default under the indenture, has occurred and is continuing. When the person to whom our assets are conveyed, transferred or leased has assumed our obligations under the debt securities and the indenture, we will be discharged from all our obligations under the debt securities and the indenture except in limited circumstances.

This covenant would not apply to any recapitalization transaction, a change of control affecting us or a highly leveraged transaction, unless the transaction or change of control were structured to include a merger or consolidation or conveyance, transfer or lease of all or substantially all of our assets.

The following are events of default under the indentures with respect to any series of debt securities that we may issue:

An event of default for a particular series of debt securities does not necessarily constitute an event of default for any other series of debt securities issued under the indenture. For each series of debt securities, any modifications to the above events of default will be described in the applicable prospectus supplement for those debt securities.

The indenture provides that if an event of default specified in the first, second, third, fourth or sixth bullets above occurs and is continuing, either the trustee or the holders of at least 25% in aggregate principal amount of the outstanding debt securities of that series may declare the principal

amount of all those debt securities (or, in the case of discount securities or indexed securities, that portion of the principal amount as may be specified in the terms of that series) to be due and payable immediately. If an event of default specified in the fifth bullet above occurs and is continuing, then the principal amount of all those debt securities (or, in the case of discount securities or indexed securities, that portion of the principal amount as may be specified in the terms of that series) will be due and payable immediately, without any declaration or other act on the part of the trustee or any holder. In certain cases, the holders of a majority in principal amount of the outstanding debt securities of any series may, on behalf of holders of all those debt securities, waive any past default and consequences of such default.

A holder of the debt securities of any series will only have the right to institute a proceeding under the indentures or to appoint a receiver or trustee, or to seek other remedies if:

We will be required to file annually with the trustee a certificate, signed by one of our officers, stating whether or not the officer knows of any default by us in the performance, observance or fulfillment of any condition or covenant of the indenture.

We and the trustee may change an indenture without the consent of any holders with respect to specific matters:

Any provision of the indenture shall automatically be deemed to have been modified, eliminated or added to the extent required to be made as a result of an amendment to the Trust Indenture Act.

The indenture also provides that we and the trustee may, with the consent of the holders of not less than a majority in aggregate principal amount of debt securities of each series of debt securities affected by such supplemental indenture then outstanding, add any provisions to, or change in any manner, eliminate or modify in any way the provisions of, the indenture or any supplemental indenture or modify in any manner the rights of the holders of the debt securities. We and the trustee may not, however, without the consent of the holder of each outstanding debt security affected thereby:

The indenture provides that the holders of not less than a majority in aggregate principal amount of the then outstanding debt securities of any series, by notice to the relevant trustee, may on behalf of the holders of the debt securities of that series waive any default and its consequences under the indenture except:

We can discharge or decrease our obligations under the indenture as stated below.

We may discharge obligations to holders of any series of debt securities that have not already been delivered to the trustee for cancellation and that have either become due and payable or are by their terms to become due and payable, or are scheduled for redemption, within one year. We may effect a discharge by irrevocably depositing with the trustee cash or government obligations denominated in the currency of the debt securities, as trust funds, in an amount certified to be enough to pay when due, whether at maturity, upon redemption or otherwise, the principal of, and any premium and interest on, the debt securities and any mandatory sinking fund payments.

Unless otherwise provided in the applicable prospectus supplement, we may also discharge any and all of our obligations to holders of any series of debt securities at any time, which we refer to as defeasance. We may also be released from the obligations imposed by any covenants of any outstanding series of debt securities and provisions of the indenture, and we may omit to comply with those covenants without creating an event of default under the trust declaration, which we refer to as covenant defeasance. We may effect defeasance and covenant defeasance only if, among other things:

In the case of a defeasance by us, the opinion we deliver must be based on a ruling of the Internal Revenue Service issued, or a change in U.S. federal income tax law occurring, after the date of the indenture.

Although we may discharge or decrease our obligations under the indenture as described in the preceding paragraphs, we may not discharge certain enumerated obligations, including but not limited to, our duty to register the transfer or exchange of any series of debt securities, to replace any temporary, mutilated, destroyed, lost or stolen series of debt securities or to maintain an office or agency in respect of any series of debt securities.

The indenture provides that there may be more than one trustee under the indenture, each for one or more series of debt securities. If there are different trustees for different series of debt securities, each trustee will be a trustee of a trust under the indenture separate and apart from the trust administered by any other trustee under that indenture. Except as otherwise indicated in this prospectus or any prospectus supplement, any action permitted to be taken by a trustee may be taken by such trustee only on the one or more series of debt securities for which it is the trustee under the indenture. Any trustee under the indenture may resign or be removed from one or more series of debt securities.

The indenture provides that, except during the continuance of an event of default, the trustee will perform only such duties as are specifically set forth in the indenture. During the existence of an event of default, the trustee will exercise those rights and powers vested in it under the indenture and use the same degree of care and skill in its exercise as a prudent person would exercise under the circumstances in the conduct of such person's own affairs.

The trustee may engage in other transactions with us. If it acquires any conflicting interest relating to any duties concerning the debt securities, however, it must eliminate the conflict or resign as trustee.

No Individual Liability of Incorporators, Stockholders, Officers or Directors

The indenture provides that no past, present or future director, officer, stockholder or employee of ours, any of our affiliates, or any successor corporation, in their capacity as such, shall have any individual liability for any of our obligations, covenants or agreements under the debt securities or the indenture.

The indentures and the debt securities will be governed by and construed in accordance with the laws of the State of New York, except to the extent that the Trust Indenture Act is applicable.

The subordinated debt securities will be unsecured and will be subordinate and junior in priority of payment to certain of our other indebtedness to the extent described in a prospectus supplement. The indenture does not limit the amount of subordinated debt securities that we may issue. It also does not limit us from issuing any other secured or unsecured debt.

Set forth below is a summary of the guarantee that may be issued by one or more of our Co-Registrants (each Co-Registrant guarantor, a guarantor; and if more than one, collectively, the guarantors) in connection with each issuance of a series of debt securities. This summary is not complete and you should read the detailed provisions of the guarantee, which will be filed as an exhibit to the applicable prospectus supplement.

Under each guarantee, the guarantors will fully, irrevocably, absolutely and unconditionally guarantee to pay any payments required to be made by us under debt securities which shall become due and payable regardless of whether such payment is due at maturity, on an interest payment date or as a result of redemption or otherwise (the "scheduled payments") but shall be unpaid by us (the "guaranteed amounts"). However, in no event shall the guaranteed amounts under a guarantee exceed the principal amount of the debt securities, plus accrued but unpaid interest, less any amounts previously paid by us pursuant to the terms of the debt securities.

In the event we do not make a scheduled payment when due (the "payment notice date") then the indenture trustee may present a payment notice in writing to the guarantors on or after the payment notice date, and the guarantors will be required to immediately pay the guaranteed amounts. Each guarantee will be an unsecured, unsubordinated and contingent obligation of the guarantors ranking equally with all other unsecured and unsubordinated obligations of the guarantors. In the event of our insolvency or receivership, the guarantors may incur limitations in receiving any distributions from us. In such an event, the guarantors may have limited resources to satisfy their obligations under the

guarantees. The guarantor's obligations under each guarantee will be effectively subordinated to all existing and future debt and liabilities of the guarantors.

An event of default under each guarantee will occur upon the failure of the guarantors to perform any of their payment obligations thereunder. The indenture trustee, on behalf of the holders of the applicable series of debt securities, has the right to enforce the obligations of the guarantors under the applicable guarantee and may institute any legal proceeding directly against the guarantors without first instituting a legal proceeding against us. Bankruptcy or similar events relating to the guarantors, the failure of any guarantee to be in full force and effect and any revocation of any guarantee by the guarantors will not constitute events of default under such guarantee.

Each guarantee will terminate and be of no further force and effect with respect to the applicable funding agreement upon the full payment of the scheduled payments or upon the earlier extinguishment of our obligations under the relevant funding agreement.

Each guarantee will be governed by, and construed in accordance with, the laws of the State of New York without regard to conflict of law principles.

We are authorized to issue 500,000,000 shares of common stock, no par value per share. On June 13, 2012, there were 182,223,025 shares of common stock outstanding.

The holders of our common stock are entitled to one vote for each share held of record on all matters submitted to a vote of the shareholders, including the election of directors. Cumulative voting for directors is not permitted. Accordingly, the holders of a majority of the shares of common stock and our 2012 Exchangeable Shares (other than those owned by McEwen Mining and its subsidiaries) entitled to vote in any election of directors can elect all of the directors standing for election, if they so choose. Subject to preferences that may be applicable to any then outstanding Preferred Stock, holders of common stock are entitled to receive ratably those dividends, if any, as may be declared by the board of directors out of legally available funds. Upon our liquidation, dissolution or winding up, the holders of common stock will be entitled to share ratably in the net assets legally available for distribution to shareholders after the payment of all of our debts and other liabilities of our Company, subject to the prior rights of any Preferred Stock then outstanding. Holders of common stock have no preemptive or conversion rights or other subscription rights and there are no redemption or sinking funds provisions applicable to the common stock. Our Articles of Incorporation and Bylaws do not include any provision that would delay, defer or prevent a change in control of our Company. However, pursuant to the laws of the State of Colorado, certain significant transactions would require the affirmative vote of a majority of the shares eligible to vote at a meeting of shareholders which requirement could result in delays to or greater cost associated with a change in control of the Company.

Our 2012 Exchangeable Shares, as more fully described beginning on page 33, are exchangeable on a one-for-one basis at any time at the option of the holder of such exchangeable shares into shares of our common stock.

The transfer agent and registrar for our common stock is Computershare Investor Services, Inc.

Our common stock, as more fully described beginning on page 32 of this prospectus, is listed on the New York Stock Exchange and on the Toronto Stock Exchange, each under the symbol "MUX." Our 2012 Exchangeable Shares are listed on the Toronto Stock Exchange under the symbol "MAQ."

The Company may offer by means of this prospectus warrants for the purchase of its debt securities or common stock, which we refer to as debt warrants and warrants, respectively. The Company may issue warrants separately or together with any other securities offered by means of this prospectus, and the warrants may be attached to or separate from such securities. Each series of warrants may be issued under a separate warrant agreement (each a "Warrant Agreement") to be entered into between the Company and a warrant agent specified therein. The warrant agent will act solely as an agent of the Company in connection with the warrants of such series and will not assume any obligation or relationship of agency or trust for or with any holders or beneficial owners of warrants.

The applicable prospectus supplement will describe the following terms, where applicable, of the warrants in respect of which this prospectus is being delivered:

The Company may issue or distribute subscription rights to its shareholders to purchase shares of common stock, debt warrants, warrants, or other securities. Each series of subscription rights may be

issued independently or together with any other security offered hereby and may or may not be transferrable by the shareholder receiving the subscription rights in such offering. In connection with any offering of subscription rights, the Company may enter into a standby underwriting, backstop or other arrangement with one or more underwriters or other persons pursuant to which the underwriters or other persons would purchase any securities remaining unsubscribed for after such subscription rights offering. Each series of subscription rights will be issued under a separate subscription rights agreement to be entered into between the Company and a bank or trust company, as subscription rights agent, all as set forth in the prospectus supplement relating to the particular issue of subscription rights. The subscription rights agent will act solely as an agent of the Company in connection with the certificates relating to the subscription rights of such series and will not assume any obligation or relationship of agency or trust for or with any holders of subscription rights certificates or beneficial owners of subscription rights. The applicable prospectus supplement relating to any subscription rights the Company offers, if any, will, to the extent applicable, describe the terms of the subscription rights to be issued, including some or all of the following:

Each subscription right will entitle the holder of subscription rights to purchase for cash the principal amount of shares of our common stock, debt warrants, warrants, or other securities at the exercise price provided in the applicable prospectus supplement. Subscription rights may be exercised at any time up to the close of business on the expiration date for the subscription rights provided in the applicable prospectus supplement. After the close of business on the expiration date, all unexercised subscription rights will be void and of no further force and effect.

Holders may exercise subscription rights as described in the applicable prospectus supplement. Upon receipt of payment and the subscription rights certificate properly completed and duly executed at the corporate trust office of the rights agent or any other office indicated in the prospectus supplement, we will, as soon as practicable, forward the shares of common stock, the debt warrants or warrants, or other securities purchasable upon exercise of the subscription rights. If less than all of the subscription rights issued in any rights offering are exercised, we may offer any unsubscribed shares of common stock, debt warrants or warrants, or other securities directly to persons, which may be to or

through agents, underwriters or dealers or through a combination of such methods, including pursuant to standby underwriting arrangements, as described in the applicable prospectus supplement.

These summaries are not complete. When we issue or distribute subscription rights, we will provide the specific terms of the rights in a prospectus supplement. To the extent the information contained in the prospectus supplement differs from this summary description, you should rely on the information in the prospectus supplement. The description in the applicable prospectus supplement of any subscription rights the Company offers or distributes will not necessarily be complete and will be qualified in its entirety by reference to the applicable subscription rights certificate, which will be filed with the SEC if the Company offers subscription rights. The subscription rights agreement and the subscription rights certificates relating to each series of subscription rights will be filed with the SEC and incorporated by reference as an exhibit to the registration statement of which this prospectus is a part.

The Company may issue subscription receipts that may be exchanged for debt securities (which may be guaranteed by one or more of our Co-Registrants), common stock, debt warrants or warrants, which may be offered separately or together with any other securities offered by means of this prospectus, as the case may be, all as set forth in the prospectus supplement relating to the particular issue of subscription receipts. Each series of subscription receipts will be issued under a separate subscription receipts agreement or indenture to be entered into between the Company and a transfer agent, as subscription receipts agent, all as set forth in the prospectus supplement relating to the particular issue of subscription receipts. The subscription receipts agent will act solely as an agent of the Company in connection with the certificates relating to the subscription receipts of such series and will not assume any obligation or relationship of agency or trust for or with any holders of subscription receipts certificates or beneficial owners of subscription receipts. The subscription receipts agreement or indenture and the subscription receipts certificates relating to each series of subscription receipts will be filed with the SEC and incorporated by reference as an exhibit to the registration statement of which this prospectus is a part.

The applicable prospectus supplement will describe the terms of the subscription receipts to be issued, including the following:

The securities offered by means of this prospectus may be issued in whole or in part in book-entry form, which means that beneficial owners of the securities will not receive certificates, notes representing the debt securities, guarantees of the Co-Registrants, warrants, subscription rights or subscription receipts representing their ownership interests in the securities, except in the event the book-entry system for the securities is discontinued. Securities issued in book-entry form will be evidenced by one or more global securities that will be deposited with, or on behalf of, a depositary identified in the applicable prospectus supplement relating to the securities. Unless and until it is exchanged in whole or in part for the individual securities represented thereby, a global security may not be transferred except as a whole by the depository for the global security to a nominee of such depository or by a nominee of such depository to such depository or another nominee of such depository or by the depository or any nominee of such depository to a successor depository or a nominee of such successor. Global securities may be issued in either registered or bearer form and in either temporary or permanent form. The specific terms of the depositary arrangement with respect to a class or series of securities that differ from the terms described here will be described in the applicable prospectus supplement.

Unless otherwise indicated in the applicable prospectus supplement, the Company anticipates that the following provisions will apply to depository arrangements.

Upon the issuance of a global security, the depository for the global security or its nominee will credit on its book-entry registration and transfer system the respective principal amounts of the individual securities represented by such global security to the accounts of persons that have accounts with such depository, who are called "participants." Such accounts shall be designated by the underwriters, dealers or agents with respect to the securities or by the Company if the securities are offered and sold directly by the Company. Ownership of beneficial interests in a global security will be limited to the depository's participants or persons that may hold interests through such participants. Ownership of beneficial interests in the global security will be shown on, and the transfer of that ownership will be effected only through, records maintained by the applicable depository or its nominee (with respect to beneficial interests of participants) and records of the participants (with respect to beneficial interests of persons who hold through participants). The laws of some states require that certain purchasers of securities take physical delivery of such securities in definitive form. Such limits and laws may impair the ability to own, pledge or transfer beneficial interest in a global security.

So long as the depository for a global security or its nominee is the registered owner of such global security, such depository or nominee, as the case may be, will be considered the sole owner or holder of the securities represented by such global security for all purposes under the indenture or other instrument defining the rights of a holder of the securities. Except as provided below or in the applicable prospectus supplement, owners of beneficial interest in a global security will not be entitled to have any of the individual securities of the series represented by such global security registered in their names, will not receive or be entitled to receive physical delivery of any such securities in definitive form and will not be considered the owners or holders thereof under the indenture or other instrument defining the rights of the holders of the securities.

Payments of amounts payable with respect to individual securities represented by a global security registered in the name of a depository or its nominee will be made to the depository or its nominee, as the case may be, as the registered owner of the global security representing such securities. None of the Company, its officers and directors or any trustee, paying agent or security registrar for an individual series of securities will have any responsibility or liability for any aspect of the records relating to or payments made on account of beneficial ownership interests in the global security for such securities or for maintaining, supervising or reviewing any records relating to such beneficial ownership interests.

The Company expects that the depository for a series of securities offered by means of this prospectus or its nominee, upon receipt of any payment of principal, premium, interest, dividend or other amount in respect of a permanent global security representing any of such securities, will immediately credit its participants' accounts with payments in amounts proportionate to their respective beneficial interests in the principal amount of such global security for such securities as shown on the records of such depository or its nominee. The Company also expects that payments by participants to owners of beneficial interests in such global security held through such participants will be governed by standing instructions and customary practices, as is the case with securities held for the account of customers in bearer form or registered in "street name." Such payments will be the responsibility of such participants.

If a depository for a series of securities at any time is unwilling, unable or ineligible to continue as depository and a successor depository is not appointed by the Company within 90 days, the Company will issue individual securities of such series in exchange for the global security representing such series of securities. In addition, the Company, at any time and in its sole discretion, but subject to any limitations described in the applicable prospectus supplement relating to such securities, may determine not to have any securities of such series represented by one or more global securities and, in such event, will issue individual securities of such series in exchange for the global security or securities representing such series of securities.

The Company may sell securities offered by means of this prospectus in and outside the United States (1) to or through underwriters or dealers, (2) directly to purchasers, (3) through agents, (4) in a rights offering, (5) as a dividend or distribution to our existing shareholders or other securityholders, (6) through a combination of any of these methods or (7) through any other method permitted by applicable law and described in a prospectus supplement. The prospectus supplement relating to the offered securities will set forth the terms of the offering, including:

We may use one or more underwriters in the sale of the offered securities, in which case the offered securities will be acquired by the underwriter or underwriters for their own account and may be resold from time to time in one or more transactions either:

The Company may directly solicit offers to purchase our securities and may sell such securities directly to institutional investors or others, who may be deemed to be underwriters within the meaning of the Securities Act with respect to any resale thereof. The Company will describe the terms of direct sales in the prospectus supplement.

Agents designated by the Company may solicit offers to purchase the securities from time to time. The prospectus supplement will name any such agent involved in the offer or sale of the securities and will set forth any commissions payable by us to such agent. Unless otherwise indicated in such prospectus supplement, any such agent will be acting on a reasonable best efforts basis for the period of its appointment. Any such agent may be deemed to be an underwriter of the securities so offered and sold.

If the Company utilizes an underwriter in the sale of the securities offered by this prospectus, the Company will execute an underwriting agreement with the underwriter or underwriters at the time of sale. We will provide the name of any underwriter in the prospectus supplement that the underwriter will use to make resales of the securities to the public. In connection with a sale of securities offered by means of this prospectus, underwriters may be deemed to have received compensation from the Company in the form of underwriting discounts or commissions and may also receive commissions from purchasers of securities for whom they may act as agent. Underwriters may sell securities offered by means of this prospectus to or through dealers, and such dealers may receive compensation in the form of discounts, concessions or commissions from the underwriters and/or commissions from the purchasers for whom they may act as agent. Any underwriting compensation paid by the Company 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.

Underwriters, dealers and agents may be entitled, under agreements that may be entered into with the Company, to indemnification against certain civil liabilities, including liabilities under the Securities Act, or to any contribution with respect to payments which they may be required to make in respect thereof and may engage in transactions with, or perform services for, us in the ordinary course of business.

If the Company uses delayed delivery contracts, the Company will, directly or through agents, underwriters or dealers, disclose that it is using them in the prospectus supplement and state when it will demand payment and delivery of the securities under the delayed delivery contracts. The Company may further agree to adjustments before a public offering to the underwriters' purchase price for the securities based on changes in the market value of the securities. The prospectus supplement relating to any such public offering will contain information on the number of securities to be sold, the manner of sale or other distribution, and other material facts relating to the public offering. These delayed delivery contracts will be subject only to the conditions that the Company sets forth in the prospectus supplement.

To facilitate the offering of securities, certain persons participating in the offering may engage in transactions that stabilize, maintain or otherwise affect the price of the securities. This may include over-allotments or short sales of the securities, which involve the sale by persons participating in the offering of more securities than the Company sold to them. In these circumstances, these persons would cover such over-allotments or short positions by exercising their over-allotment option, if any, or making purchases in the open market. In addition, these persons may stabilize or maintain the price of the securities by bidding for or purchasing securities in the open market or by imposing penalty bids, whereby selling concessions allowed to dealers participating in the offering may be reclaimed if

securities sold by them are repurchased in connection with stabilization transactions. The effect of these transactions may be to stabilize or maintain the market price of the securities at a level above that which might otherwise prevail in the open market. These transactions may be discontinued at any time.

In addition, the Company may enter into derivative transactions with third parties, or sell securities not covered by this prospectus to third parties in privately negotiated transactions. If the applicable prospectus supplement so indicates, in connection with those derivatives, the third parties may sell securities covered by this prospectus and the applicable prospectus supplement, including in short sale transactions. If so, the third party may use securities pledged by us or borrowed from us or others to settle those sales or to close out any related open borrowings of stock, and may use securities received from us in settlement of those derivatives to close out any related open borrowings of stock. The third party in such sale transactions will be an underwriter and will be identified in the applicable prospectus supplement. In addition, the Company may otherwise loan or pledge securities to a financial institution or other third party that in turn may sell the securities short using this prospectus and an applicable prospectus supplement. Such financial institution or other third party may transfer its economic short position to investors in our securities or in connection with a concurrent offering of other securities.

Other than the common stock, all securities offered by this prospectus will be a new issue of securities with no established trading market. Any underwriter to whom securities are sold by us for public offering and sale may make a market in such securities, but such underwriters may not be obligated to do so and may discontinue any market making at any time without notice. The securities may or may not be listed on a national securities exchange or a foreign securities exchange, except for the common stock which is currently listed and traded on the New York Stock Exchange and the Toronto Stock Exchange. Any common stock sold by this prospectus will be listed for trading on the New York Stock Exchange subject to official notice of issuance. The Company cannot give you any assurance as to the liquidity of the trading markets for any securities.

Agents, underwriters and dealers may be customers of, engage in transactions with, or perform services for, us and our subsidiaries in the ordinary course of business.

Our authorized capital consists of 500,000,000 shares of common stock, no par value, and two shares of preferred stock, no par value. As of June 13, 2012, there were a total of 182,223,025 shares of our common stock issued and outstanding and one share of preferred stock designated as Series B Special Voting Preferred Stock (the "Series B Preferred Share") that is issued and outstanding, with the other undesignated and not issued nor outstanding.

The following discussion summarizes the rights and privileges of our outstanding capital stock and certain securities that may be convertible into our capital stock and is qualified by reference to the relevant provisions of the laws of the State of Colorado and our Amended and Restated Articles of Incorporation (our "Articles of Incorporation") and Bylaws which have been filed with the SEC and are incorporated by reference into the registration statement of which this prospectus is a part.

The holders of our common stock are entitled to one vote for each share held of record on all matters submitted to a vote of the shareholders, including the election of directors. Cumulative voting for directors is not permitted. Subject to preferences that may be applicable to any then outstanding preferred stock, holders of common stock are entitled to receive ratably those dividends, if any, as may be declared by our board of directors out of legally available funds. Upon our liquidation, dissolution or winding up, the holders of common stock will be entitled to share ratably in the net assets legally available for distribution to shareholders after the payment of all of our debts and other liabilities of our Company, subject to the prior rights of any preferred stock then outstanding. Holders of common

stock have no preemptive or conversion rights or other subscription rights and there are no redemption or sinking funds provisions applicable to the common stock. Our Articles of Incorporation and our Bylaws do not include any provision that would delay, defer or prevent a change in control of our Company. However, pursuant to the laws of the State of Colorado, certain significant transactions would require the affirmative vote of a majority of the shares eligible to vote at a meeting of shareholders which requirement could result in delays to or greater cost associated with a change in control of McEwen Mining.

Of the two shares of preferred stock authorized under our Articles of Incorporation, one share is designated as the Series B Preferred Share, which is issued and outstanding, and the other share of preferred stock, which was previously issued and outstanding and designated as the Series A Preferred Share (the "Series A Preferred Share"), which is undesignated and not issued nor outstanding. Other than the one share of undesignated preferred stock, our Articles of Incorporation do not include authorization for any other undesignated class or "blank check" preferred stock, and any issuance of preferred stock would require shareholder approval.

The Series B Preferred Share was issued in connection with the acquisition of Minera Andes in January 2012 to facilitate the issuance of the exchangeable shares (the "2012 Exchangeable Shares") of our indirect wholly-owned subsidiary, McEwen Mining—Minera Andes Acquisition Corp. ("Canadian Exchange Co."). The Series B Preferred Share is held by a trustee under a voting and exchange trust agreement and will be outstanding so long as any of the 2012 Exchangeable Shares are outstanding, excluding any such shares owned by McEwen Mining or its subsidiaries.

The Series B Preferred Share entitles the holder thereof to an aggregate number of votes on all matters submitted to the vote of the holders of shares of our common stock equal to the number of 2012 Exchangeable Shares issued and outstanding from time to time and which are not owned by McEwen Mining or its subsidiaries. As of June 13, 2012, the Series B Preferred Share was entitled to 85,921,359 votes, based upon 85,921,359 2012 Exchangeable Shares outstanding on such date, which are not owned by McEwen Mining or its subsidiaries. Except as otherwise provided herein or by law, the holder of the Series B Preferred Share and the holders of our common stock vote together as one class on all matters submitted to the vote of the holders of shares of our common stock. The holder of the Series B Preferred Share has no special voting rights, and its consent is not required, except to the extent it is entitled to vote with the holders of shares of our common stock, for taking any corporate action.

At such time as (a) the Series B Preferred Share entitles its holder to a number of votes equal to zero because there are no 2012 Exchangeable Shares issued and outstanding that are not owned by McEwen Mining and its subsidiaries, and (b) there is no share of stock, debt, option or other agreement, obligation or commitment of Canadian Exchange Co. which could by its terms require Canadian Exchange Co. to issue any 2012 Exchangeable Shares to any person other than us, then the Series B Preferred Share will thereupon be retired and cancelled promptly thereafter. Such Series B Preferred Share will upon its cancellation, and upon the taking of any action required by applicable law, become an authorized but unissued share of preferred stock and may be reissued as part of a new series of preferred stock to be created by resolution or resolutions of our board of directors, subject to the conditions and restrictions on issuance under applicable law or set forth in our Articles of Incorporation or our Bylaws.

If the Series B Preferred Share should be purchased or otherwise acquired by us in any manner whatsoever, then such Series B Preferred Share will be retired and cancelled promptly after the

acquisition thereof. Such share will upon its cancellation, and upon the taking of any action required by applicable law, become an authorized but unissued share of preferred stock and may be reissued as part of a new series of preferred stock to be created by resolution or resolutions of our board of directors, subject to the conditions and restrictions on issuance under applicable law or set forth in our Articles of Incorporation or our Bylaws.

The holder of the Series B Preferred Share is not entitled to receive any portion of any dividend or distribution at any time. The Series B Preferred Share is not redeemable.

Upon any liquidation, dissolution or winding up of McEwen Mining, the holder of the Series B Preferred Share will not be entitled to any portion of any related distribution.

The 2012 Exchangeable Shares were issued by our subsidiary, Canadian Exchange Co., in connection with the acquisition of Minera Andes. As of June 13, 2012, there were approximately 85,921,359 2012 Exchangeable Shares outstanding that were not held by McEwen Mining or its subsidiaries. The 2012 Exchangeable Shares are exchangeable on a one-for-one basis at any time at the option of the holder of the 2012 Exchangeable Shares into shares of McEwen Mining common stock. The following is a summary description of the material provisions of the rights, privileges, restrictions and conditions attaching to the 2012 Exchangeable Shares.

Subject to applicable law and the due exercise by either us or our direct wholly-owned subsidiary, McEwen Mining (Alberta) ULC ("Callco"), of our or its retraction call right, holders of the 2012 Exchangeable Shares are entitled at any time to retract (i.e., to require Canadian Exchange Co. to redeem) any or all exchangeable shares held by them and to receive in exchange for each 2012 Exchangeable Share, one share of common stock of McEwen Mining, plus the dividend amount, which is equal to any cash dividends declared and payable but not yet paid on the 2012 Exchangeable Shares, any dividends declared and payable or paid on shares of our common stock that have not yet been declared or paid on the 2012 Exchangeable Shares and an amount representing the value of any non-cash dividends declared and payable but not yet paid on the 2012 Exchangeable Shares, if any. Holders of 2012 Exchangeable Shares may effect a retraction by presenting to Canadian Exchange Co. or its transfer agent the certificate(s) representing the 2012 Exchangeable Shares the holder desires to be redeemed by Canadian Exchange Co. or the equivalent thereof, if any, together with such other documents and instruments as may be required under the Business Corporations Act (Alberta), the Articles of Incorporation of Canadian Exchange Co. or by its transfer agent, and a duly executed retraction request specifying that the holder desires to have the number of retracted shares specified therein redeemed by Canadian Exchange Co. A holder of retracted shares may withdraw its retraction request, by written notice to Canadian Exchange Co., before the close of business on the business day immediately preceding the retraction date, in which case the retraction request will be null and void and the revocable offer constituted by the retraction request will be deemed to have been revoked.

Upon receipt by Canadian Exchange Co. or its transfer agent of a retraction request and certificate(s) representing the 2012 Exchangeable Shares to be redeemed or the equivalent thereof, if any, Canadian Exchange Co. will immediately provide notice of such request to us and Callco. Instead of Canadian Exchange Co. redeeming the retracted shares, and provided that the retraction request is not revoked by the holder of 2012 Exchangeable Shares, we will have the right to purchase, and to the extent the right is not exercised by us, Callco will have the right to purchase, all but not less than all of the shares covered by the retraction request, which we refer to as our retraction call right. See the section entitled "—Retraction Call Right" below.

If, as a result of solvency requirement provisions or other provisions of applicable law, Canadian Exchange Co. is not permitted to redeem all 2012 Exchangeable Shares tendered by a retracting holder and neither we nor Callco has exercised its retraction call right, Canadian Exchange Co. will redeem up to the maximum permissible number of 2012 Exchangeable Shares tendered by the holder. We or Callco will be required to purchase any 2012 Exchangeable Shares not redeemed by Canadian Exchange Co. in exchange for shares of McEwen Mining common stock on the retraction date under the optional exchange right described below.

Subject to applicable law and the exercise by either us or Callco of our or its liquidation call right, in the event of the liquidation, dissolution or winding up of Canadian Exchange Co. or any other distribution of its assets among its shareholders for the purpose of winding up its affairs, holders of 2012 Exchangeable Shares shall be entitled to receive from the assets of Canadian Exchange Co. a liquidation payment that will be satisfied by the issuance of one share of our common stock plus the dividend amount, if any, for each outstanding 2012 Exchangeable Share. This liquidation amount will be paid to the holders of 2012 Exchangeable Shares before any distribution of assets of Canadian Exchange Co. is made to the holders of the common shares or any other shares of Canadian Exchange Co. ranking junior to the 2012 Exchangeable Shares and is subject to the exercise by us or Callco of our or its liquidation call right described in the section entitled "—Liquidation Call Right" below.

In the event of McEwen Mining's liquidation, dissolution or winding up or any other distribution of its assets for the purposes of winding up its affairs, all of the then outstanding 2012 Exchangeable Shares will be automatically exchanged for shares of McEwen Mining common stock. To effect an automatic exchange, McEwen Mining will purchase all of the 2012 Exchangeable Shares from the holders on the last business day prior to the effective date of a liquidation. The purchase price payable for each 2012 Exchangeable Share purchased in a liquidation of McEwen Mining will be satisfied by the issuance of one share of McEwen Mining common stock plus the dividend amount, if any.

Subject to applicable law and the due exercise by either us or Callco of our or its redemption call right, Canadian Exchange Co. will, on the redemption date, redeem all of the then outstanding 2012 Exchangeable Shares for a purchase price equal to one share of McEwen Mining's common stock for each outstanding 2012 Exchangeable Share plus the dividend amount, if any. The redemption date for the 2012 Exchangeable Shares will be the date, if any, established by the board of directors of Canadian Exchange Co. for the redemption by Canadian Exchange Co. of all but not less than all of the outstanding 2012 Exchangeable Shares, which date will be no earlier than January 24, 2022, being the tenth anniversary of the effective date of the acquisition of Minera Andes, unless one of the conditions described in the paragraphs below is met.

Subject to applicable law, and provided that neither we nor Callco have exercised the redemption call right, Canadian Exchange Co. will redeem all of the outstanding 2012 Exchangeable Shares upon at least 30 days prior notice to the holders of the 2012 Exchangeable Shares.

The board of directors of Canadian Exchange Co. may accelerate the redemption date in the event that:

Subject to applicable law and the Articles of Incorporation of Canadian Exchange Co., Canadian Exchange Co. may at any time purchase for cancellation all or any part of the outstanding 2012 Exchangeable Shares by private agreement with any holder of such 2012 Exchangeable Shares or by tender to all holders of record of the 2012 Exchangeable Shares or through the facilities of any stock exchange on which the 2012 Exchangeable Shares are listed or quoted at any price per share together with the dividend amount for which the record date has occurred prior to the date of purchase.

As further described below, we and Callco have certain overriding rights to acquire 2012 Exchangeable Shares from the holders thereof. In each case, we have the initial call right and to the extent we do not exercise our right, Callco may exercise its right. A holder of 2012 Exchangeable Shares will be subject to different Canadian federal income tax consequences depending upon whether

the call rights are exercised and by which entity and whether the relevant 2012 Exchangeable Shares are redeemed by Canadian Exchange Co. if the call rights are not exercised.

Each of we and Callco has an overriding change of law call right to purchase (or to cause Callco to purchase) from all but not less than all of the holders of 2012 Exchangeable Shares (other than McEwen Mining and its subsidiaries) all but not less than all of the 2012 Exchangeable Shares held by each such holder in the event of any amendment to the Income Tax Act (Canada) and other applicable provincial income tax laws that permits holders of 2012 Exchangeable Shares who (a) are resident in Canada, (b) hold their 2012 Exchangeable Shares as capital property, and (c) deal at arm's length with us or Canadian Exchange Co., to exchange their 2012 Exchangeable Shares without requiring such holders to recognize any gain or loss or any actual or deemed dividend in respect of such exchange for the purposes of the Income Tax Act (Canada) or applicable provincial income tax laws. The purchase price under the change of law call right is satisfied by delivering to the holder of 2012 Exchangeable Shares one share of our common stock of McEwen Mining for each 2012 Exchangeable Share purchased plus the dividend amount, if any. In the event of the exercise of the change of law call right by us or Callco, as the case may be, each holder of 2012 Exchangeable Shares shall be obligated to sell all the 2012 Exchangeable Shares held by such holder to us or Callco, as the case may be, on the change of law call date upon payment by us to such holder of the purchase price for each such 2012 Exchangeable Share. To exercise the change of law call right, we or Callco must notify the transfer agent of our or its intention to exercise such right at least 45 days before the date on which we or Callco intend to acquire the 2012 Exchangeable Shares. The transfer agent will notify the holders of 2012 Exchangeable Shares as to whether we or Callco have exercised the change of law call right forthwith after receiving notice from us or Callco.

Notwithstanding the foregoing, neither we nor Callco shall be entitled to exercise the change of law call right if more than 5% of the 2012 Exchangeable Shares are held by U.S. residents.

Under the share provisions, each of we and Callco has an overriding retraction call right to acquire all but not less than all of the 2012 Exchangeable Shares that a holder of 2012 Exchangeable Shares requests Canadian Exchange Co. to redeem on the retraction date. Callco is only entitled to exercise its retraction call right with respect to those holders of 2012 Exchangeable Shares, if any, for which we have not exercised our retraction call right. The purchase price under the retraction call right is satisfied by delivering to the holder of 2012 Exchangeable Shares one share of our common stock for each 2012 Exchangeable Share purchased plus the dividend amount, if any.

At the time of a retraction request by a holder of 2012 Exchangeable Shares, Canadian Exchange Co. will immediately notify us and Callco and either we or Callco must then advise Canadian Exchange Co. within five business days if we choose to exercise the retraction call right. If we or Callco do not advise Canadian Exchange Co. within the five-business day period, Canadian Exchange Co. will notify the holder as soon as possible thereafter that neither of us will exercise the retraction call right. Unless the holder revokes his or her retraction request, on the retraction date the 2012 Exchangeable Shares that the holder has requested Canadian Exchange Co. to redeem will be acquired by us or Callco (assuming either we or Callco exercise the retraction call right) or redeemed by Canadian Exchange Co., as the case may be, in each case for the retraction call purchase price as described in the preceding paragraph.

Under the share provisions, each of we and Callco have an overriding liquidation call right, in the event of and notwithstanding a proposed liquidation, dissolution or winding up of Canadian Exchange Co., to acquire all but not less than all of the 2012 Exchangeable Shares then outstanding (other than 2012 Exchangeable Shares held by McEwen Mining or our subsidiaries). Callco is only entitled to exercise its liquidation call right with respect to those holders of 2012 Exchangeable Shares, if any, for which we have not exercised our liquidation call right. The purchase price under the liquidation call right is satisfied by delivering to the holder of 2012 Exchangeable Shares one share of our common stock for each 2012 Exchangeable Share purchased plus the dividend amount, if any. Upon the exercise by us or Callco of the liquidation call right, the holders will be obligated to transfer their 2012 Exchangeable Shares to us or Callco, as the case may be, for the purchase price described above. The acquisition by us or Callco of all of the outstanding 2012 Exchangeable Shares upon the exercise of the liquidation call right will occur on the effective date of the voluntary or involuntary liquidation, dissolution or winding up of Canadian Exchange Co.

To exercise the liquidation call right, we or Callco must notify Canadian Exchange Co.'s transfer agent in writing, as agent for the holders of the 2012 Exchangeable Shares, the trustee and Canadian Exchange Co. of our or Callco's intention to exercise this right at least 30 days before the liquidation date in the case of a voluntary liquidation, dissolution or winding up of Canadian Exchange Co. and at least five business days before the liquidation date in the case of an involuntary liquidation, dissolution or winding up of Canadian Exchange Co. The transfer agent will notify the holders of 2012 Exchangeable Shares as to whether or not we or Callco have exercised the liquidation call right after the earlier of (a) the date notice of exercise has been provided to the transfer agent and (b) the expiry of the date by which the same may be exercised by us or Callco. If we or Callco exercise the liquidation call right on the liquidation date, we or Callco will purchase and the holders will sell all of the 2012 Exchangeable Shares for an amount equal to the liquidation call exercise price as described in the preceding paragraph.

Under the share provisions, we and Callco have an overriding redemption call right, notwithstanding any proposed redemption of the 2012 Exchangeable Shares by Canadian Exchange Co., to acquire all but not less than all of the 2012 Exchangeable Shares then outstanding (other than 2012 Exchangeable Shares held by us or our subsidiaries). Callco is only entitled to exercise its redemption call right with respect to those holders of 2012 Exchangeable Shares, if any, for which we have not exercised our redemption call right. The purchase price under the redemption call right will be satisfied by delivering to the holder one share of McEwen Mining common stock plus the dividend amount, if any. In the event of the exercise of the redemption call right by us or Callco, as the case may be, each holder of 2012 Exchangeable Shares will be obligated to sell all their 2012 Exchangeable Shares to us or Callco, as the case may be, on the redemption date upon payment by us or Callco, as the case may be, to such holder of the purchase price for such 2012 Exchangeable Shares.

To exercise the redemption call right, we or Callco must notify Canadian Exchange Co.'s transfer agent in writing, as agent for the holders of the 2012 Exchangeable Shares, and Canadian Exchange Co. of our or Callco's intention to exercise this right at least 30 days before the redemption date (other than in the case of an accelerated redemption date described above, in which case we or Callco, as the case may be, must notify the transfer agent and Canadian Exchange Co. on or before the redemption date). The transfer agent will notify the holders of 2012 Exchangeable Shares as to whether or not we or Callco exercised the redemption call right after the earlier of (a) the date notice of exercise has been provided to the transfer agent and (b) the expiry of the date by which the same may be exercised by us or Callco. If we or Callco exercise the redemption call right on the redemption date,

we or Callco will purchase and the holders will sell all of the 2012 Exchangeable Shares for an amount equal to the redemption call purchase price as described in the preceding paragraph.

If McEwen Mining or Callco exercises one or more of its call rights, shares of our common stock will be directly issued to holders of 2012 Exchangeable Shares and we or Callco, as the case may be, will become the holder of the 2012 Exchangeable Shares. We or Callco will not be entitled to exercise any voting rights attached to the 2012 Exchangeable Shares that are acquired from the holders. If we or Callco decline to exercise the call rights when applicable, we will be required, under a support agreement, to issue shares of our common stock to the holders of 2012 Exchangeable Shares.

The number of directors of Canadian Exchange Co. is fixed at three and the rights attaching to the 2012 Exchangeable Shares entitle holders of 2012 Exchangeable Shares a limited right to vote on the election or appointment of one director but such holders have no rights to vote on the election of the remaining two directors. In addition, the holders of the exchangeable shares are entitled to receive notice of any meeting of the shareholders of Canadian Exchange Co. and to attend and vote thereat, except those meetings where only holders of a specified class or particular series of shares are entitled to vote, and each holder of 2012 Exchangeable Shares is entitled to one vote per 2012 Exchangeable Share in person or by proxy.

Holders of 2012 Exchangeable Shares are entitled to a preference over holders of any common shares of Canadian Exchange Co. and any other shares ranking junior to the 2012 Exchangeable Shares with respect to the payment of dividends and the distribution of assets in the event of the liquidation, dissolution or winding up of Canadian Exchange Co., whether voluntary or involuntary, or any other distribution of the assets of Canadian Exchange Co. among its shareholders for the purpose of winding up its affairs.

Holders of 2012 Exchangeable Shares are entitled to receive dividends equivalent to the dividends, if any, paid from time to time by us on shares of our common stock. The declaration date, record date and payment date for dividends on the 2012 Exchangeable Shares must be the same as that for any corresponding dividends on shares of our common stock.

The rights, privileges, restrictions and conditions attaching to the 2012 Exchangeable Shares may be added to, changed or removed only with the approval of the holders of the 2012 Exchangeable Shares. Any approval required to be given by the holders of the 2012 Exchangeable Shares to add to, change or remove any right, privilege, restriction or condition attaching to the 2012 Exchangeable Shares or any other matter requiring the approval or consent of the holders of the 2012 Exchangeable Shares as a separate class (other than the election of a single director) shall be deemed to have been sufficiently given if it has been given in accordance with applicable law, subject to a minimum requirement that such approval be evidenced by a resolution passed by not less than 66²/3% of the votes cast on such resolution, excluding 2012 Exchangeable Shares beneficially owned by us or any of our subsidiaries, at a meeting of holders of 2012 Exchangeable Shares duly called and held at which the holders of at least 10% of the outstanding 2012 Exchangeable Shares at that time are present or represented by proxy.

Previously Issued Series A Special Voting Preferred Stock and 2007 Exchangeable Shares

A Series A Preferred Share was issued in connection with the acquisition of White Knight Resources Ltd., Nevada Pacific Gold Ltd. and Tone Resources Limited in 2007 to facilitate the issuance of exchangeable shares ("2007 Exchangeable Shares") of our wholly-owned indirect subsidiary, US Gold Canadian Acquisition Corporation ("2007 Acquisition Co."). The 2007 Exchangeable Shares were exchangeable on a one-for-one basis into shares of our common stock. On March 26, 2012, we announced that the board of directors of 2007 Acquisition Co. established a redemption date of May 30, 2012 for all of the then outstanding 2007 Exchangeable Shares and that US Gold Alberta ULC, our wholly-owned indirect subsidiary ("Alberta ULC") elected to exercise its overriding redemption call right to acquire all of the then outstanding 2007 Exchangeable Shares (other than the 2007 Exchangeable Shares held by McEwen Mining and its subsidiaries) on May 29, 2012. In accordance with the Articles of Incorporation of 2007 Acquisition Co., after May 29, 2012, all holders of 2007 Exchangeable Shares have no further rights as holders thereof other than the right to receive shares of our common stock. As of May 29, 2012, there were 2,494,849 2007 Exchangeable Shares not held by McEwen Mining and its subsidiaries for which our shares of common stock had not yet been exchanged. In accordance with our Articles of Incorporation, as a result of there not being any outstanding 2007 Exchangeable Shares nor shares of stock, debt, options or other agreements, obligations or commitments of 2007 Acquisition Co. which could by its terms require 2007 Acquisition Co. to issue 2007 Exchangeable Shares to any person, the Series A Preferred Share was retired and cancelled and became an authorized but unissued share of preferred stock.

Computershare Investor Services Inc. is the transfer agent for our common stock. The principal office of Computershare is located at 250 Royall Street, Canton, MA, 02021 and its telephone number is (303) 262-0600.

Computershare Investor Services Inc. is the transfer agent for the 2012 Exchangeable Shares. Its principal office is located at 100 University Avenue, 9^th Floor, North Tower, Toronto, Ontario M5J 2Y1 and its telephone number is (514) 982-7555.

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 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 room. Our SEC filings also are available to the public on the SEC's Internet site at www.sec.gov. In addition, we maintain an Internet website that contains information about us, including our SEC filings, at www.mcewenmining.com. The information contained on our website does not constitute a part of this prospectus.

The SEC allows us to "incorporate by reference" in this prospectus certain information we file with the SEC, which means that we may disclose important information in this 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, and the information we file later with the SEC will automatically update and supersede the information filed earlier. We incorporate by reference the documents listed below and any filings we make with the SEC under Section 13(a), 13(c), 14 or 15(d) of the Exchange Act after the initial filing of the registration statement that contains this prospectus and until the offering of the securities covered by this prospectus is completed; 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 in this prospectus, at no cost, by writing or telephoning to:

McEwen Mining Inc.
181 Bay Street, Bay Wellington Tower, Suite 4750
P.O. Box 792
Toronto, ON
Canada M5J 2T3
Attn: Investor Relations
(866)-441-0690

Readers should rely only on the information provided or incorporated by reference in this prospectus or in any applicable supplement to this prospectus. Readers should not assume that the information in this prospectus, any post-effective amendment and any applicable supplement is accurate as of any date other than the date on the front cover of the document.

Our consolidated financial statements as of December 31, 2011 and for each of the years in the three-year period ended December 31, 2011, and management's assessment of the effectiveness of internal control over financial reporting as of December 31, 2011 have been incorporated by reference in this prospectus in reliance upon the reports of KPMG LLP, Toronto, Canada, independent registered public accounting firm, which have been incorporated by reference herein upon the authority of said firm as experts in accounting and auditing.

In connection with particular offerings of securities in the future, the legal validity of the securities will be passed upon for us by underwriters, dealers or agents, and counsel named in the applicable prospectus supplement.

The following table sets forth the costs and expenses, other than underwriting discounts and commissions, payable by us in connection with the sale and distribution of the securities being registered. All amounts except the SEC registration fee and the NASD filing fee are estimated.


SEC Registration Fee*	$	22,920
FINRA Filing Fee		20,500
Listing Fees**		[•]
Accounting Fees and Expenses**		[•]
Legal Fees and Expenses**		[•]
Printing and Mailing Expenses**		[•]
Trustee's Fees and Expenses**		[•]
Subscription Agent's Fees and Expenses**		[•]
Information Agent's Fees and Expenses**		[•]
Miscellaneous Fees and Expenses**		[•]
Total		[•]

*: $1,540 of which is offset pursuant to Rule 457(p) under the Securities Act by a credit from previously paid fees related to unsold securities registered as part of McEwen Mining's registration statement on Form S-3 (Registration No. 333-157998) filed with the Securities and Exchange Commission on March 16, 2009 under the name US Gold Corporation.
**: These fees will be dependent on the type of securities and number of offerings and, therefore, cannot be estimated at this time. In accordance with Rule 430B of the Securities Act, additional information regarding estimated fees and expenses will be provided at the time information as to an offering is included in a prospectus supplement.

We have entered into indemnification agreements with each of our executive officers and directors which provide that we must indemnify, to the fullest extent permitted by the laws of the State of Colorado, but subject to certain exceptions, any of our directors or officers who are made or threatened to be made a party to a proceeding, by reason of the person serving or having served in their capacity as an executive officer or director with us. We may also be required to advance expenses of defending any proceeding brought against them while serving in such capacity.

Our Articles of Incorporation and Bylaws provide that we must indemnify, to the fullest extent permitted by the laws of the State of Colorado, any of our directors, officers, employees or agents made or threatened to be made a party to a proceeding, by reason of the person serving or having served in a capacity as such, against judgments, penalties, fines, settlements and reasonable expenses incurred by the person in connection with the proceeding if certain standards are met.

The Colorado Business Corporation Act ("CBCA") allows indemnification of directors, officers, employees and agents of a company against liabilities incurred in any proceeding in which an individual is made a party because he or she was a director, officer, employee or agent of the company if such person conducted himself in good faith and reasonably believed his actions were in, or not opposed to, the best interests of the company, and with respect to any criminal action or proceeding, had no reasonable cause to believe his conduct was unlawful. A person must be found to be entitled to indemnification under this statutory standard by procedures designed to assure that disinterested

members of the board of directors have approved indemnification or that, absent the ability to obtain sufficient numbers of disinterested directors, independent counsel or shareholders have approved the indemnification based on a finding that the person has met the standard. Indemnification is limited to reasonable expenses.

Our Articles of Incorporation limit the liability of our directors to the fullest extent permitted by the CBCA. Specifically, our directors will not be personally liable for monetary damages for breach of fiduciary duty as directors, except for:

Liability under federal securities law is not limited by our Articles of Incorporation.

Insofar as indemnification for liabilities arising under the Securities Act may be permitted to directors, officers and controlling persons of the registrant pursuant to the foregoing provisions, or otherwise, the registrant has been advised that in the opinion of the United States Securities and Exchange Commission such indemnification is against public policy as expressed in the Securities Act and is, therefore, unenforceable. In the event that a claim for indemnification against such liabilities (other than the payment by the registrant of expenses incurred or paid by a director, officer or controlling person of the registrant in the successful defense of any action, suit or proceeding) is asserted by such director, officer or controlling person in connection with the securities being registered, the registrant will, unless in the opinion of its counsel the matter has been settled by controlling precedent, submit to a court of appropriate jurisdiction the question, whether such indemnification by it is against public policy as expressed in the Securities Act and will be governed by the final adjudication of such issue.

The Exhibit Index filed herewith and appearing immediately before the exhibits hereto is incorporated by reference.

(b) The undersigned registrant hereby undertakes that, for purposes of determining any liability under the Securities Act of 1933, each filing of the registrant's annual report pursuant to Section 13(a) or 15(d) of the Securities Exchange Act of 1934 (and, where applicable, each filing of an employee benefit plan's annual report pursuant to Section 15(d) of the Securities Exchange Act of 1934) that is incorporated by reference in the registration statement shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof.

(c) That, if the undersigned registrant uses this registration statement to offer securities to its existing security holders upon the exercise of warrants or subscription rights and any securities not taken by security holders are to be reoffered to the public, then the undersigned registrant will supplement the applicable prospectus supplement, after the expiration of the subscription period, to set forth the results of the subscription offer, the transactions by the underwriters during the subscription period, the amount of unsubscribed securities to be purchased by the underwriters, and the terms of any subsequent reoffering thereof. If any public offering by the underwriters is to be made on terms differing from those set forth on the cover page of the applicable prospectus supplement, a post-effective amendment will be filed to set forth the terms of such offering.

(d) Insofar as indemnification for liabilities arising under the Securities Act of 1933 may be permitted to directors, officers and controlling persons of the registrant pursuant to the foregoing provisions, or otherwise, the registrant has been advised that in the opinion of the Securities and Exchange Commission such indemnification is against public policy as expressed in the Securities Act of 1933 and is, therefore, unenforceable. In the event that a claim for indemnification against such liabilities (other than the payment by the registrant of expenses incurred or paid by a director, officer or controlling person of the registrant in the successful defense of any action, suit or proceeding) is asserted by such director, officer or controlling person in connection with the securities being registered, the registrant will, unless in the opinion of its counsel the matter has been settled by controlling precedent, submit to a court of appropriate jurisdiction the question whether such indemnification by it is against public policy as expressed in the Securities Act of 1933 and will be governed by the final adjudication of such issue.

(e) The undersigned registrant hereby further undertakes to file an application for the purpose of determining the eligibility of the trustee to act under subsection (a) of Section 310 of the Trust Indenture Act in accordance with the rules and regulations prescribed by the SEC under Section 305(b)(2) of the Trust Indenture Act.

Pursuant to the requirements of the Securities Act of 1933, the registrant certifies that it has reasonable grounds to believe that it meets all of the requirements for filing on Form S-3 and has duly caused this registration statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of Toronto, Province of Ontario, on June 18, 2012.

Each person whose signature appears below hereby constitutes and appoints Perry Y. Ing, his true and lawful attorney-in-fact and agent, with full power of substitution and resubstitution for him in any and all capacities, to sign any or all amendments or post-effective amendments to this registration statement, or any registration statement for the same offering that is to be effective upon filing pursuant to Rule 462(b) under the Securities Act of 1933, as amended (the "Securities Act of 1933"), and to file the same, with all exhibits and other documents in connection therewith, with the Securities and Exchange Commission, and to execute, deliver and file any other documents and instruments in the undersigned's name or on the undersigned's behalf which said attorneys-in-fact and agents, or either of them, may determine to be necessary or advisable to comply with the Securities Act of 1933and any rules or regulations promulgated thereunder, granting unto said attorneys-in-fact and agents, and each of them, full power and authority to do and perform each and every act and thing requisite and necessary in connection with such matters and hereby ratifying and confirming all that said attorneys-in-fact and agents, or either of them, or their substitutes, may lawfully do or cause to be done by virtue of the power of attorney granted hereby.

Pursuant to the requirements of the Securities Act of 1933, this registration statement has been signed as of June 18, 2012 by the following persons in the capacities indicated


Signature		Title

/s/ LEANNE M. BAKER Leanne M. Baker		Director
/s/ DONALD QUICK Donald Quick		Director
/s/ MICHAEL L. STEIN Michael L. Stein		Director
/s/ ALLEN V. AMBROSE Allen V. Ambrose		Director
/s/ RICHARD W. BRISSENDEN Richard W. Brissenden		Director

Pursuant to the requirements of the Securities Act of 1933, this registration statement has been signed as of June 18, 2012 by the following persons in the capacities indicated.

Each person whose signature appears below hereby constitutes and appoints Perry Y. Ing, his true and lawful attorney-in-fact and agent, with full power of substitution and resubstitution for him in any and all capacities, to sign any or all amendments or post-effective amendments to this registration statement, or any registration statement for the same offering that is to be effective upon filing pursuant to Rule 462(b) under the Securities Act of 1933, as amended (the "Securities Act of 1933"), and to file the same, with all exhibits and other documents in connection therewith, with the Securities and Exchange Commission, and to execute, deliver and file any other documents and instruments in the undersigned's name or on the undersigned's behalf which said attorneys-in-fact and agents, or either of them, may determine to be necessary or advisable to comply with the Securities Act of 1933 and any rules or regulations promulgated thereunder, granting unto said attorneys-in-fact and agents, and each of them, full power and authority to do and perform each and every act and thing requisite and necessary in connection with such matters and hereby ratifying and confirming all that said attorneys-in-fact and agents, or either of them, or their substitutes, may lawfully do or cause to be done by virtue of the power of attorney granted hereby.