Filed Pursuant to Rule 424(b)(2)

Registration No. 333-142346

CALCULATION OF REGISTRATION FEE

	Proposed	Proposed	Proposed
	Maximum	Maximum	Maximum
Title of Each Class of	Amount to	Aggregate Price	Aggregate	Registration
Securities to Be Registered	Be Registered	Per Share	Offering Price	Fee
Common Stock, par value $.01 per share	$74,520,000	100%	$74,520,000	$2,287.77(1)

(1) Such fee was paid by the Registrant by wire transfer on September 12, 2007.

PROSPECTUS SUPPLEMENT

(To Prospectus Dated April 25, 2007)

1,800,000 Shares

Carrizo Oil & Gas, Inc.

Common Stock

We are offering 1,800,000 shares of our common stock to selected accredited investors. In this offering, RBC Capital Markets Corporation is acting as our managing placement agent. The placement agents are not required to sell any minimum number or dollar amount of securities but will use their reasonable best efforts to sell the securities offered. There is no assurance that any of such securities will be sold.

Our common stock is listed on the NASDAQ Global Select Market under the symbol “CRZO.” On September 11, 2007, the last reported sale price of our common stock on the NASDAQ Global Select Market was $43.58 per share.

Investing in our common stock involves risks. See “Risk Factors” beginning on page S-3 of this prospectus supplement and on page 2 of the accompanying prospectus.

PRICE $41.40 PER SHARE

	Per Share(1)		Total(1)
Public offering price	$	41.4000	$	74,520,000
Placement agents’ commissions(2)	$	1.2995	$	2,339,100
Proceeds, before reimbursements and expenses, to us	$	40.1005	$	72,180,900

(1)	Assumes that all 1,800,000 shares of common stock offered by this prospectus supplement are sold in this offering. There is no requirement that any minimum number of shares or dollar amount of common stock be sold in this offering and there can be no assurance that we will sell all or any of the securities being offered.
(2)	Represents an average commission rate. See “Plan of Distribution.”

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

We expect this transaction to close on or before September 14, 2007 and to deliver the shares of common stock to investors on or about September 14, 2007.

RBC Capital Markets

September 11, 2007.

TABLE OF CONTENTS

Prospectus Supplement

	Page
FORWARD-LOOKING STATEMENTS		S-ii
SUMMARY		S-1
RISK FACTORS		S-3
USE OF PROCEEDS		S-3
CAPITALIZATION		S-4
PRICE RANGE OF COMMON STOCK		S-5
PLAN OF DISTRIBUTION		S-6
LEGAL MATTERS		S-7
EXPERTS		S-7
WHERE YOU CAN FIND MORE INFORMATION		S-7

Prospectus

CARRIZO OIL & GAS, INC	1
RISK FACTORS	2
FORWARD-LOOKING STATEMENTS	15
USE OF PROCEEDS	17
RATIO OF EARNINGS TO FIXED CHARGES AND EARNINGS TO COMBINED FIXED CHARGES AND PREFERRED STOCK DIVIDENDS	17
DESCRIPTION OF DEBT SECURITIES	17
DESCRIPTION OF CAPITAL STOCK	26
DESCRIPTION OF WARRANTS	29
PLAN OF DISTRIBUTION	30
LEGAL MATTERS	32
EXPERTS	32
WHERE YOU CAN FIND MORE INFORMATION	33

This document is in two parts. The first part is this prospectus supplement, which describes the terms of this offering of our common stock. The second part is the accompanying prospectus, which gives more general information, some of which may not apply to this offering of common stock. If the information varies between this prospectus supplement and the accompanying prospectus, you should rely on the information in this prospectus supplement. We refer to the prospectus supplement and the accompanying prospectus, taken together, as the “prospectus.”

You should rely only on the information contained or incorporated by reference in this prospectus. We have not authorized any other person to provide you with different information. If anyone provides you with different information, you should not rely on it. We are not making an offer to sell these securities in any jurisdiction where the offer or sale is not permitted. You should assume the information appearing in this prospectus supplement and the accompanying prospectus is accurate only as of the date on the cover of this prospectus supplement or the accompanying prospectus and that any information we have incorporated by reference is accurate only as of the date of the document incorporated by reference. Our business, financial condition, results of operations and prospects may have changed since that date.

S-i

FORWARD-LOOKING STATEMENTS

This prospectus, including the documents incorporated by reference herein, contains statements concerning our expectations, beliefs, plans, objectives, goals, strategies, future events or performance and underlying assumptions and other statements that are not historical facts. These statements are “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995. These forward-looking statements include, among others, statements regarding:

•  our growth strategies;

•  our ability to explore for and develop natural gas and oil resources successfully and economically;

•  our estimates of the timing and number of wells we expect to drill and other exploration activities;

•  anticipated trends in our business;

•  our future results of operations;

•  our liquidity and our ability to finance our exploration and development activities;

•  our capital expenditure program;

•  future market conditions in the oil and gas industry;

•  our ability to make and integrate acquisitions; and

•  the impact of governmental regulation.

You generally can identify our forward-looking statements by the words “anticipate,” “believe,” “budgeted,” “continue,” “could,” “estimate,” “expect,” “forecast,” “goal,” “intend,” “may,” “objective,” “plan,” “potential,” “predict,” “projection,” “scheduled,” “should,” or other similar words. Such statements involve risks and uncertainties, including, but not limited to, those relating to our dependence on our exploratory drilling activities, the volatility of oil and natural gas prices, the need to replace reserves depleted by production, operating risks of oil and natural gas operations, our dependence on our key personnel, factors that affect our ability to manage our growth and achieve our business strategy, risks relating to our offshore and foreign operations, technological changes, our significant capital requirements, the potential impact of government regulations, adverse regulatory determinations, including those related to coalbed methane drilling in Montana, litigation, competition, the uncertainty of reserve information and future net revenue estimates, property acquisition risks, industry partner issues, availability of equipment, weather and other factors detailed in this prospectus and in our filings with the SEC.

We have based our forward-looking statements on our management’s beliefs and assumptions based on information available to our management at the time the statements are made. We caution you that assumptions, beliefs, expectations, intentions and projections about future events may and often do vary materially from actual results. Therefore, we cannot assure you that actual results will not differ materially from those expressed or implied by our forward-looking statements.

Some of the factors that could cause actual results to differ from those expressed or implied in forward-looking statements are described under “Risk Factors” and in other sections of this prospectus supplement and the accompanying prospectus and described under “Risk Factors” and elsewhere in the documents that we incorporate by reference into this prospectus supplement and the accompanying prospectus, including our annual report on Form 10-K for the fiscal year ended December 31, 2006 and in our other reports filed with the SEC. Should one or more of these risks or uncertainties materialize, or should underlying assumptions prove incorrect, actual outcomes may vary materially from those indicated. All subsequent written and oral forward-looking statements attributable to us or persons acting

S-ii

on our behalf are expressly qualified in their entirety by reference to these risks and uncertainties. You should not place undue reliance on our forward-looking statements. Each forward-looking statement speaks only as of the date of the particular statement, and, except as required by law, we undertake no duty to update any forward-looking statement.

S-iii

SUMMARY

This summary highlights selected information about us but does not contain all the information that may be important to you. This prospectus includes specific terms of the offering and information about our business and financial data. You should read carefully this entire prospectus supplement and the accompanying prospectus, including the matters set forth under the caption “Risk Factors,” and the information incorporated by reference in this prospectus before making an investment decision.

This prospectus supplement offers shares of common stock of Carrizo Oil & Gas, Inc. In this prospectus supplement and the accompanying prospectus, references to “Carrizo,” the “Company,” “we” and “us” refer to Carrizo Oil & Gas, Inc. and its subsidiaries.

Carrizo Oil & Gas, Inc.

We are an independent energy company engaged in the exploration, development and production of natural gas and oil. Our current operations are focused in proven, producing natural gas and oil geologic trends along the onshore Gulf Coast area in Texas and Louisiana, primarily in the Miocene, Wilcox, Frio and Vicksburg trends and the Barnett Shale area in North Texas. Our other interests include properties in East Texas, the U.K. North Sea, and acreage in shale plays in the Barnett/Woodford in West Texas/New Mexico, the Floyd/Neal in Mississippi, the western New Albany in Kentucky/Illinois and the Fayetteville in Arkansas. We also have a coalbed methane investment in the Rocky Mountains.

Our executive offices are located at 1000 Louisiana, Suite 1500, Houston, Texas 77002, and our telephone number is (713) 328-1000.

S-1

The Offering

Common Stock Offered by Us	1,800,000 shares.
Common Stock Outstanding After the Offering	27,969,526 shares.
Use of Proceeds	We intend to use the net proceeds from the offering to fund in part our capital expenditure program, including our drilling and leasing programs, and for other corporate purposes. Pending those uses, we intend to use a portion of the net proceeds to repay borrowings under our revolving credit facility. See “Use of Proceeds.”
Nasdaq Global Select Market Symbol	“CRZO”
Risk Factors	You should consider carefully the “Risk Factors” beginning on page S-3 of this prospectus supplement and page 2 of the accompanying prospectus and in our other filings with the SEC before making an investment in our common stock.

S-2

RISK FACTORS

You should consider carefully the risks described under “Risk Factors” in the accompanying prospectus and in our annual report on Form 10-K for the year ended December 31, 2006 and in our other filings with the SEC before making a decision whether to invest in our common stock. Additional risks and uncertainties described elsewhere in this prospectus or in the documents incorporated by reference in this prospectus may also adversely affect our business, operating results, financial condition and prospects, as well as the value of an investment in our common stock.

USE OF PROCEEDS

The net proceeds to us of this offering, after deducting the placement agents’ commissions and reimbursed expenses but before paying offering expenses, will be approximately $72.1 million. We expect to use substantially all of these proceeds to fund in part our capital expenditure program, including our drilling and leasing programs in the Barnett Shale and appraisal well drilling in the North Sea, and for other corporate purposes. Pending those uses, we intend to use a portion of the net proceeds to repay the $50.0 million of outstanding borrowings under our revolving credit facility that matures on May 25, 2010. As of September 10, 2007, $50 million principal amount, bearing interest at a weighted average rate of 7.2%, was outstanding under our revolving credit facility. We originally borrowed this amount to fund our ongoing exploration program and other corporate purposes.

S-3

CAPITALIZATION

The following table sets forth our unaudited cash and capitalization as of June 30, 2007:

•  on an actual basis; and

•  on an as-adjusted basis to give effect to the sale of 1,800,000 shares of common stock in this offering at a public offering price of $41.40 per share and the temporary application of the net proceeds as set forth under the heading “Use of Proceeds.”

You should read this table in conjunction with our consolidated financial statements and related notes that are incorporated by reference in this prospectus supplement.

	June 30, 2007
	Actual			As Adjusted
	(In thousands)
Cash	$	7,503		$	47,419
Long-term debt:
Second Lien Credit Facility	$	219,375		$	219,375
Senior Secured Revolving Credit Facility		32,000			—
Other		5			5
Total long-term debt	$	251,375		$	219,375
Shareholders’ Equity:
Preferred stock, par value $0.01 (10,000,000 shares authorized; none outstanding)	$	—		$	—
Common stock, par value $0.01 (40,000,000 shares authorized with 26,163,959 issued and outstanding (27,969,526 shares as adjusted))		262			280
Additional paid in capital		173,347			245,245
Retained earnings		55,467			55,467
Accumulated other comprehensive loss		10,390			10,390
Unearned compensation		(8,568	)		(8,568	)
Total shareholders’ equity		230,898			302,814
Total capitalization	$	482,272		$	522,189

S-4

PRICE RANGE OF COMMON STOCK

On September 11, 2007, we had 26,169,526 shares of common stock outstanding, beneficially held by approximately 3,386 holders. Our common stock is listed on the Nasdaq Global Select Market under the symbol “CRZO.”

The closing price of our common stock on September 11, 2007 as reported on the Nasdaq Global Select Market was $43.58 per share. The following table shows the high and low sales prices of our common stock during 2005, 2006, the first and second quarters of 2007 and the third quarter of 2007 through September 11, 2007.

	High		Low
1st Quarter 2005	$	17.58	$	9.93
2nd Quarter 2005		18.33		13.10
3rd Quarter 2005		31.63		16.93
4th Quarter 2005		30.60		21.81
1st Quarter 2006		29.70		21.57
2nd Quarter 2006		32.95		24.99
3rd Quarter 2006		32.42		24.31
4th Quarter 2006		33.94		23.08
1st Quarter 2007		35.58		25.54
2nd Quarter 2007		47.70		34.44
3rd Quarter 2007 (through September 11, 2007)		44.46		34.51

S-5

PLAN OF DISTRIBUTION

We have entered into a placement agent agreement dated September 10, 2007, with RBC Capital Markets Corporation, or RBC. Subject to the terms and conditions set forth in the agreement, RBC has agreed to act as our managing placement agent in connection with this offering. RBC and the other placement agents are not purchasing any shares of common stock offered by this prospectus supplement or the accompanying prospectus, nor are they required to arrange for the purchase or sale of any specific number or dollar amount of the shares of common stock, but have agreed to use reasonable best efforts to arrange for the sale of all of the shares offered.

RBC has entered into an agreement among placement agents with the other placement agents in this offering, Capital One Southcoast, Inc., Johnson Rice & Company L.L.C., BMO Capital Markets Corp., KeyBanc Capital Markets Inc., Pritchard Capital Partners LLC, Tudor, Pickering & Co, Securities, Inc., Howard Weil Incorporated, Coker & Palmer, Inc., SunTrust Robinson Humphrey, Inc., FIG Partners, LLC, and Natixis Bleichroeder Inc. Subject to the terms and conditions set forth in the agreement, the placement agents have authorized RBC to act as their representative in connection with this offering.

There is no requirement that any minimum number of shares or dollar amount of shares of common stock be sold in this offering and there can be no assurance that we will sell all or any of the shares being offered.

The securities purchase agreements with purchasers of shares of our common stock which are to be sold pursuant to this prospectus supplement and the accompany prospectus provide that the obligations of the purchasers are subject to certain conditions precedent, including, among other things, the absence of any material adverse change in our business and the receipt of certain opinions, letters and certificates from our independent registered public accounting firm, our independent consulting petroleum engineers and us.

Confirmations and definitive prospectuses will be distributed to all investors who agree to purchase shares of common stock, informing investors of the closing date as to such shares. We currently anticipate that closing of this offering will take place on or about September 14, 2007. Investors will also be informed of the date on which they must transmit the purchase price into the designated account.

We have agreed to pay RBC commissions of (i) 3.25% of the gross proceeds from the sale of up to 1,600,000 shares of common stock sold in the offering, a portion of which commissions will be allocated to the other placement agents, and (ii) 2.25% of the gross proceeds from the sale of any shares of common stock sold in the offering in excess of 1,600,000 shares. We will also reimburse RBC for up to $65,000 of reasonable out-of-pocket expenses, including legal fees, incurred by it in connection with this offering.

In compliance with the guidelines of the Financial Industry Regulatory Authority, or FINRA, we will not provide any FINRA member or independent broker/dealer with underwriter compensation in excess of 8% of the public offering price of the shares of common stock sold by such FINRA member or independent broker/dealer that have been registered under the registration statement of which this prospectus supplement forms a part for such shares of common stock sold pursuant to such registration statement.

RBC proposes to arrange for the sale to one or more purchasers of the shares of common stock offered pursuant to this prospectus supplement and the accompanying prospectus directly through securities purchase agreements between each of the purchasers and us. We estimate the total expenses of this offering which will be payable by us, excluding commissions and reimbursed expenses to the placement agent, will be approximately $200,000.

S-6

We have agreed to indemnify the placement agents against certain liabilities, including liabilities under the Securities Act of 1933, as amended, and liabilities arising from breaches of representations and warranties contained in the placement agent agreement. We have also agreed to contribute to payments the placement agents may be required to make in respect of such liabilities.

The securities purchase agreement with investors in this offering will be included as an exhibit to our Current Report on Form 8-K that will be filed with the Securities and Exchange Commission prior to the consummation of this offering.

RBC has informed us that it will not engage in overallotment, stabilizing transactions or syndicate covering transactions in connection with this offering.

The transfer agent for our common stock is American Stock Transfer & Trust Company.

In connection with the offering, the following executive officers and directors, whose combined common stock ownership in us represents approximately 12.2% of the outstanding shares of our common stock, have agreed that, for a period of 30 days beginning on the date of this prospectus supplement, such persons may not offer, sell, pledge or otherwise dispose of the shares of common stock that they beneficially own, including securities that are convertible into shares of common stock and securities that are exchangeable or exercisable for shares of common stock, without the prior written consent of RBC, subject to certain exceptions: S.P. Johnson IV, Paul F. Boling, J. Bradley Fisher, Gregory E. Evans, Steven A. Webster, Thomas L. Carter, Jr., Paul B. Loyd, Jr., F. Gardner Parker, Roger A. Ramsey and Richard H. Smith. The restrictions contained in these agreements may be waived by RBC, in its discretion, without public notice.

LEGAL MATTERS

The validity of the issuance of the common stock and certain other legal matters in connection with the issuance of the common stock will be passed upon for us by Baker Botts L.L.P., Houston, Texas.

EXPERTS

Our consolidated financial statements (and management’s assessment of the effectiveness of internal control over financial reporting, which is included in Management’s Report on Internal Control Over Financial Reporting) for the years ended December 31, 2004, 2005 and 2006, incorporated by reference in this prospectus and registration statement, have been audited by Pannell Kerr Forster of Texas, P.C., independent registered public accounting firm, to the extent indicated in their reports thereon also incorporated by reference. Such consolidated financial statements and management’s assessment of the effectiveness of internal control over financial reporting have been so incorporated herein by reference in reliance on such reports given on the authority of said firm as experts in accounting and auditing.

The letter reports of Ryder Scott Company, L.P., Fairchild & Wells, Inc. and LaRoche Petroleum Consultants, Ltd., each independent consulting petroleum engineers, and certain information with respect to our oil and gas reserves derived from such reports and certain information with respect to our oil and gas reserves derived from the reports of DeGolyer and MacNaughton, independent consulting petroleum engineers, have been incorporated by reference into this prospectus upon the authority of each such firm as experts with respect to such matters covered in such reports and in giving such reports.

WHERE YOU CAN FIND MORE INFORMATION

We file annual, quarterly and current reports, proxy statements and other information with the SEC. You may read and copy any of these documents at the SEC’s public reference room located at

S-7

100 F Street, N.E., Room 1580, Washington, D.C. 20549. Please call the SEC at 1-800-SEC-0330 for further information on the public reference room. Our SEC filings are also available to the public from commercial document retrieval services and at the web site maintained by the SEC at http://www.sec.gov and our website at http://www.carrizo.cc under “Links-SEC Documents.” Copies of these reports, proxy statements and other information concerning us can also be inspected at the offices of the Nasdaq Stock Market, Inc., which are located at 1735 K Street N.W., Washington, D.C. 20006. Information on our website or any other website is not incorporated by reference in this prospectus and does not constitute part of this prospectus.

This prospectus is part of a registration statement and, as permitted by SEC rules, does not contain all of the information included in the registration statement. Whenever a reference is made in this prospectus to any of our contracts or other documents, the reference may not be complete and, for a copy of the contract or document, you should refer to the exhibits that are part of or incorporated by reference into the registration statement.

The SEC allows us to “incorporate by reference” into this prospectus the information we file with it, which means that we can disclose important information to you by referring you to those documents. Information incorporated by reference is considered to be part of this prospectus. Any statement contained in this prospectus or a document incorporated by reference in this prospectus will be deemed to be modified or superseded for purposes of this prospectus to the extent that a statement contained in this prospectus or in any other subsequently filed document that is incorporated by reference in this prospectus modifies or superseded the statement. Any statement so modified or superseded will not be deemed, except as so modified or superseded, to constitute a part of this prospectus. We incorporate by reference the documents listed below and future filings we make with the SEC under Section 13(a), 13(c), 14 or 15(d) of the Exchange Act (excluding any information “furnished” but not “filed,” unless we specifically provide that such “furnished” information is to be incorporated by reference) after the effectiveness of this registration statement and until the termination of offerings under this prospectus:

•  our annual report on Form 10-K for the year ended December 31, 2006;

•  our definitive proxy statement filed on Schedule 14A relating to our 2007 Annual Meeting of Shareholders;

•  our current reports on Form 8-K filed on January 5, 2007, September 4, 2007 (including Item 7.01) and September 11, 2007 (including Item 7.01);

•  our quarterly report on Form 10-Q for the quarter ended March 31, 2007;

•  our quarterly report on Form 10-Q for the quarter ended June 30, 2007; and

•  the description of our common stock in our Registration Statement on Form 8-A (Registration No. 000-22915) filed on July 31, 1997.

S-8

PROSPECTUS

Carrizo Oil & Gas, Inc.

Senior Debt Securities
Subordinated Debt Securities
Common Stock
Preferred Stock
Warrants

We will provide the specific terms of the securities in supplements to this prospectus. You should read this prospectus and any supplement carefully before you invest.

Our common stock is listed on the Nasdaq Global Select Market under the symbol “CRZO.”

You should consider carefully the risk factors beginning on page 2 of this prospectus and in any applicable prospectus supplement before purchasing any of our securities.

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.

The date of this prospectus is April 23, 2007.

TABLE OF CONTENTS

	Page
Carrizo Oil & Gas, Inc.		1
Risk Factors		2
Forward-Looking Statements		15
Use of Proceeds		17
Ratio of Earnings to Fixed Charges and Earnings to Combined Fixed Charges and Preferred Stock Dividends		17
Description of Debt Securities		17
Description of Capital Stock		26
Description of Warrants		29
Plan of Distribution		30
Legal Matters		32
Experts		32
Where You Can Find More Information		33

About This Prospectus

This prospectus is part of a registration statement that we have filed with the U.S. Securities and Exchange Commission (“SEC”) using a “shelf” registration process. Using this process, we may offer any combination of the securities described in this prospectus in one or more offerings. This prospectus provides you with a general description of the securities we may offer. Each time we use this prospectus to offer securities, we will provide a prospectus supplement and, if applicable, a pricing supplement that will describe the specific terms of the offering. The prospectus supplement and any pricing supplement may also add to, update or change the information contained in this prospectus. If there is any inconsistency between the information in this prospectus and any prospectus supplement, you should rely on the information in the prospectus supplement. Please carefully read this prospectus, the prospectus supplement and any pricing supplement, in addition to the information contained in the documents we refer to under the heading “Where You Can Find More Information.”

You should rely only on the information contained in or incorporated by reference into this prospectus, the prospectus supplement and any pricing supplement. We have not authorized anyone to provide you with different information. You should assume that the information appearing in or incorporated by reference into this prospectus, any prospectus supplement and any pricing supplement is accurate only as of the date on its cover page and that any information we have incorporated by reference is accurate only as of the date of the document incorporated by reference. Our business, financial condition, results of operations and prospects may have changed since such dates.

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Carrizo Oil & Gas, Inc.

We are an independent energy company engaged in the exploration, development and production of natural gas and oil. Our current operations are focused in proven, producing natural gas and oil geologic trends along the onshore Gulf Coast area in Texas and Louisiana, primarily in the Miocene, Wilcox, Frio and Vicksburg trends, and, since mid-2003, in the Barnett Shale area in North Texas. Our other interests include properties in East Texas, the U.K. North Sea, and acreage in shale plays in the Barnett/Woodford in West Texas/New Mexico, Floyd/Neal in Mississippi, the western New Albany in Kentucky/Illinois and the Fayetteville in Arkansas. We also have a coalbed methane investment in the Rocky Mountains. Unless the context otherwise requires, all references to “we,” “us,” “our” and “the Company” refer to Carrizo Oil & Gas, Inc. and its subsidiaries. The term “you” refers to a prospective investor.

Our principal executive offices are located at 1000 Louisiana, Suite 1500, Houston, Texas 77002, and our telephone number at that location is (713) 328-1000. Information contained on our website, http://www.carrizo.net, is not part of this prospectus.

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Risk Factors

An investment in our securities involves risks. You should carefully consider all of the information contained in or incorporated by reference in this prospectus and other information which may be incorporated by reference in this prospectus or any prospectus supplement as provided under “Where You Can Find More Information,” including our Annual Reports on Form 10-K and our Quarterly Reports on Form 10-Q. This prospectus also contains forward-looking statements that involve risks and uncertainties. Please read “Forward-Looking Statements.” Our actual results could differ materially from those anticipated in the forward-looking statements as a result of certain factors, including the risks described elsewhere in this prospectus or any prospectus supplement and in the documents incorporated by reference into this prospectus or any prospectus supplement. If any of these risks occur, our business, financial condition or results of operations could be adversely affected. Additional risks not currently known to us or that we currently deem immaterial may also have a material adverse effect on us.

Risks Related to Our Company

Natural gas and oil drilling is a speculative activity and involves numerous risks and substantial and uncertain costs that could adversely affect us.

Our success will be largely dependent upon the success of our drilling program. Drilling for natural gas and oil involves numerous risks, including the risk that no commercially productive natural gas or oil reservoirs will be discovered. The cost of drilling, completing and operating wells is substantial and uncertain, and drilling operations may be curtailed, delayed or canceled as a result of a variety of factors beyond our control, including:

•  unexpected or adverse drilling conditions;

•  elevated pressure or irregularities in geologic formations;

•  equipment failures or accidents;

•  adverse weather conditions;

•  compliance with governmental requirements; and

•  shortages or delays in the availability of drilling rigs, crews and equipment.

Because we identify the areas desirable for drilling from 3-D seismic data covering large areas, we may not seek to acquire an option or lease rights until after the seismic data is analyzed or until the drilling locations are also identified; in those cases, we may not be permitted to lease, drill or produce natural gas or oil from those locations.

Even if drilled, our completed wells may not produce reserves of natural gas or oil that are economically viable or that meet our earlier estimates of economically recoverable reserves. Our overall drilling success rate or our drilling success rate for activity within a particular project area may decline. Unsuccessful drilling activities could result in a significant decline in our production and revenues and materially harm our operations and financial condition by reducing our available cash and resources. Because of the risks and uncertainties of our business, our future performance in exploration and drilling may not be comparable to our historical performance described in this prospectus, any prospectus supplement and our filings with the SEC.

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We may not adhere to our proposed drilling schedule.

Our final determination of whether to drill any scheduled or budgeted wells will be dependent on a number of factors, including:

•  the results of our exploration efforts and the acquisition, review and analysis of the seismic data;

•  the availability of sufficient capital resources to us and the other participants for the drilling of the prospects;

•  the approval of the prospects by the other participants after additional data has been compiled;

•  economic and industry conditions at the time of drilling, including prevailing and anticipated prices for natural gas and oil and the availability and prices of drilling rigs and crews; and

•  the availability of leases and permits on reasonable terms for the prospects.

Although we have identified or budgeted for numerous drilling prospects, we may not be able to lease or drill those prospects within our expected time frame or at all. Wells that are currently part of our capital budget may be based on statistical results of drilling activities in other 3-D project areas that we believe are geologically similar rather than on analysis of seismic or other data in the prospect area, in which case actual drilling and results are likely to vary, possibly materially, from those statistical results. In addition, our drilling schedule may vary from our expectations because of future uncertainties.

Our reserve data and estimated discounted future net cash flows are estimates based on assumptions that may be inaccurate and are based on existing economic and operating conditions that may change in the future.

There are uncertainties inherent in estimating natural gas and oil reserves and their estimated value, including many factors beyond the control of the producer. The reserve data incorporated by reference in this prospectus represents only estimates. Reservoir engineering is a subjective and inexact process of estimating underground accumulations of natural gas and oil that cannot be measured in an exact manner and is based on assumptions that may vary considerably from actual results.

Accordingly, reserve estimates may be subject to upward or downward adjustment, and actual production, revenue and expenditures with respect to our reserves likely will vary, possibly materially, from estimates. Additionally, there recently has been increased debate and disagreement over the classification of reserves, with particular focus on proved undeveloped reserves. Changes in interpretations as to classification standards, or disagreements with our interpretations, could cause us to write down these reserves.

As of December 31, 2006, approximately 75% of our proved reserves were proved undeveloped and proved nonproducing. Moreover, some of the producing wells included in our reserve reports as of December 31, 2006 had produced for a relatively short period of time as of that date. Because most of our reserve estimates are calculated using volumetric analysis, those estimates are less reliable than estimates based on a lengthy production history. Volumetric analysis involves estimating the volume of a reservoir based on the net feet of pay of the structure and an estimation of the area covered by the structure based on seismic analysis. In addition, realization or recognition of our proved undeveloped reserves will depend on our development schedule and plans. Lack of certainty with respect to development plans for proved undeveloped reserves could cause the discontinuation of the classification of these reserves as proved. Although we have increased our development of the Camp Hill Field in East Texas, we have in the past chosen to delay development of our proved undeveloped reserves in the Camp Hill Field in favor of pursuing shorter-term exploration projects with higher potential rates of return,

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adding to our lease position in this field and further evaluating additional economic enhancements for this field’s development.

The discounted future net cash flows incorporated by reference in this prospectus are not necessarily the same as the current market value of our estimated natural gas and oil reserves. As required by the SEC, the estimated discounted future net cash flows from proved reserves are based on prices and costs as of the date of the estimate. Actual future net cash flows also will be affected by factors such as:

•  the actual prices we receive for natural gas and oil;

•  our actual operating costs in producing natural gas and oil;

•  the amount and timing of actual production;

•  supply and demand for natural gas and oil;

•  increases or decreases in consumption of natural gas and oil; and

•  changes in governmental regulations or taxation.

In addition, the 10% discount factor we use when calculating discounted future net cash flows for reporting requirements in compliance with the Financial Accounting Standards Board Statement of Financial Accounting Standards No. 69 may not be the most appropriate discount factor based on interest rates in effect from time to time and risks associated with us or the natural gas and oil industry in general.

We depend on successful exploration, development and acquisitions to maintain reserves and revenue in the future.

In general, the volume of production from natural gas and oil properties declines as reserves are depleted, with the rate of decline depending on reservoir characteristics. Except to the extent we conduct successful exploration and development activities or acquire properties containing proved reserves, or both, our proved reserves will decline as reserves are produced. Our future natural gas and oil production is, therefore, highly dependent on our level of success in finding or acquiring additional reserves. In addition, we are dependent on finding partners for our exploratory activity. To the extent that others in the industry do not have the financial resources or choose not to participate in our exploration activities, we will be adversely affected.

Natural gas and oil prices are highly volatile, and lower prices will negatively affect our financial results.

Our revenue, profitability, cash flow, future growth and ability to borrow funds or obtain additional capital, as well as the carrying value of our properties, are substantially dependent on prevailing prices of natural gas and oil. Historically, the markets for natural gas and oil prices have been volatile, and those markets are likely to continue to be volatile in the future. It is impossible to predict future natural gas and oil price movements with certainty. Prices for natural gas and oil are subject to wide fluctuation in response to relatively minor changes in the supply of and demand for natural gas and oil, market uncertainty and a variety of additional factors beyond our control. These factors include:

•  the level of consumer product demand;

•  overall economic conditions;

•  weather conditions;

•  domestic and foreign governmental relations, regulations and taxes;

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•  the price and availability of alternative fuels;

•  political conditions;

•  the level and price of foreign imports of oil and liquefied natural gas; and

•  the ability of the members of the Organization of Petroleum Exporting Countries to agree upon and maintain production constraints and oil price controls.

Declines in natural gas and oil prices may materially adversely affect our financial condition, liquidity and ability to finance planned capital expenditures and results of operations.

We face strong competition from other natural gas and oil companies.

We encounter competition from other natural gas and oil companies in all areas of our operations, including the acquisition of exploratory prospects and proven properties. Our competitors include major integrated natural gas and oil companies and numerous independent natural gas and oil companies, individuals and drilling and income programs. Many of our competitors are large, well-established companies that have been engaged in the natural gas and oil business much longer than we have and possess substantially larger operating staffs and greater capital resources than we do. These companies may be able to pay more for exploratory projects and productive natural gas and oil properties and may be able to define, evaluate, bid for and purchase a greater number of properties and prospects than our financial or human resources permit. In addition, these companies may be able to expend greater resources on the existing and changing technologies that we believe are and will be increasingly important to attaining success in the industry. Such competitors may also be in a better position to secure oilfield services and equipment on a timely basis or on favorable terms. We may not be able to conduct our operations, evaluate and select suitable properties and consummate transactions successfully in this highly competitive environment.

We may not be able to keep pace with technological developments in our industry.

The natural gas and oil industry is characterized by rapid and significant technological advancements and introductions of new products and services using new technologies. As others use or develop new technologies, we may be placed at a competitive disadvantage, and competitive pressures may force us to implement those new technologies at substantial cost. In addition, other natural gas and oil companies may have greater financial, technical and personnel resources that allow them to enjoy technological advantages and may in the future allow them to implement new technologies before we can. We may not be able to respond to these competitive pressures and implement new technologies on a timely basis or at an acceptable cost. If one or more of the technologies we use now or in the future were to become obsolete or if we are unable to use the most advanced commercially available technology, our business, financial condition and results of operations could be materially adversely affected.

We are subject to various governmental regulations and environmental risks.

Natural gas and oil operations are subject to various federal, state and local government regulations that may change from time to time. Matters subject to regulation include discharge permits for drilling operations, plug and abandonment bonds, reports concerning operations, the spacing of wells, unitization and pooling of properties and taxation. From time to time, regulatory agencies have imposed price controls and limitations on production by restricting the rate of flow of natural gas and oil wells below actual production capacity in order to conserve supplies of natural gas and oil. Other federal, state and local laws and regulations relating primarily to the protection of human health and the environment apply to the development, production, handling, storage, transportation and disposal of natural gas and oil, by-products thereof and other substances and materials produced or used in connection with natural gas and

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oil operations. In addition, we may be liable for environmental damages caused by previous owners of property we purchase or lease. As a result, we may incur substantial liabilities to third parties or governmental entities and may be required to incur substantial remediation costs. Further, we or our affiliates hold certain mineral leases in the State of Montana that require coalbed methane drilling permits, the issuance of which has been challenged in pending litigation. We may not be able to obtain new permits in an optimal time period or at all. We also are subject to changing and extensive tax laws, the effects of which cannot be predicted. Compliance with existing, new or modified laws and regulations could have a material adverse effect on our business, financial condition and results of operations.

We are subject to various operating and other casualty risks that could result in liability exposure or the loss of production and revenues.

The natural gas and oil business involves operating hazards such as:

•  well blowouts;

•  mechanical failures;

•  explosions;

•  uncontrollable flows of oil, natural gas or well fluids;

•  fires;

•  geologic formations with abnormal pressures;

•  pipeline ruptures or spills;

•  releases of toxic gases; and

•  other environmental hazards and risks.

Any of these hazards and risks can result in the loss of hydrocarbons, environmental pollution, personal injury claims and other damage to our properties and the property of others.

Offshore operations are subject to a variety of operating risks, such as capsizing, collisions and damage or loss from hurricanes or other adverse weather conditions. These conditions can and have caused substantial damage to facilities and interrupt production. Our operations in the U.K. North Sea are dependent upon the availability, proximity and capacity of pipelines, natural gas gathering systems and processing facilities. Any significant change affecting these infrastructure facilities could materially harm our business. We deliver crude oil and natural gas through gathering systems and pipelines that we do not own. These facilities may be temporarily unavailable due to adverse weather conditions or may not be available to us in the future. As a result, we could incur substantial liabilities or experience reductions in revenue that could reduce or eliminate the funds available for our exploration and development programs and acquisitions, or result in the loss of properties.

A substantial portion of our operations is exposed to the additional risk of tropical weather disturbances.

A substantial portion of our production and reserves is located onshore South Louisiana and Texas. Operations in this area are subject to tropical weather disturbances. Some of these disturbances can be severe enough to cause substantial damage to facilities and possibly interrupt production. For example, a number of our wells in the Gulf Coast were shut in following Hurricanes Katrina and Rita in 2005. In accordance with customary industry practices, we maintain insurance against some, but not all, of these risks.

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Losses could occur for uninsured risks or in amounts in excess of existing insurance coverage. We cannot assure you that we will be able to maintain adequate insurance in the future at rates we consider reasonable or that any particular types of coverage will be available. An event that is not fully covered by insurance could have a material adverse effect on our financial position and results of operations.

We may not have enough insurance to cover all of the risks we face.

We maintain insurance against losses and liabilities in accordance with customary industry practices and in amounts that management believes to be prudent; however, insurance against all operational risks is not available to us. We do not carry business interruption insurance. We may elect not to carry insurance if management believes that the cost of available insurance is excessive relative to the risks presented. In addition, we cannot insure fully against pollution and environmental risks. The occurrence of an event not fully covered by insurance could have a material adverse effect on our financial condition and results of operations.

We cannot control the activities on properties we do not operate and are unable to ensure their proper operation and profitability.

We do not operate all of the properties in which we have an interest. As a result, we have limited ability to exercise influence over, and control the risks associated with, operations of these properties. The failure of an operator of our wells to adequately perform operations, an operator’s breach of the applicable agreements or an operator’s failure to act in ways that are in our best interests could reduce our production and revenues. The success and timing of our drilling and development activities on properties operated by others therefore depend upon a number of factors outside of our control, including the operator’s:

•  timing and amount of capital expenditures;

•  expertise and financial resources;

•  inclusion of other participants in drilling wells; and

•  use of technology.

The marketability of our natural gas production depends on facilities that we typically do not own or control, which could result in a curtailment of production and revenues.

The marketability of our production depends in part upon the availability, proximity and capacity of natural gas gathering systems, pipelines and processing facilities. We generally deliver natural gas through gas gathering systems and gas pipelines that we do not own under interruptible or short-term transportation agreements. Under the interruptible transportation agreements, the transportation of our gas may be interrupted due to capacity constraints on the applicable system, for maintenance or repair of the system, or for other reasons as dictated by the particular agreements. Our ability to produce and market natural gas on a commercial basis could be harmed by any significant change in the cost or availability of such markets, systems or pipelines.

Our future acquisitions may yield revenues or production that varies significantly from our projections.

In acquiring producing properties, we assess the recoverable reserves, future natural gas and oil prices, operating costs, potential liabilities and other factors relating to the properties. Our assessments are necessarily inexact and their accuracy is inherently uncertain. Our review of a subject property in connection with our acquisition assessment will not reveal all existing or potential problems or permit us to become sufficiently familiar with the property to assess fully its deficiencies and capabilities. We may

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not inspect every well, and we may not be able to observe structural and environmental problems even when we do inspect a well. If problems are identified, the seller may be unwilling or unable to provide effective contractual protection against all or part of those problems. Any acquisition of property interests may not be economically successful, and unsuccessful acquisitions may have a material adverse effect on our financial condition and future results of operations.

Our business may suffer if we lose key personnel.

We depend to a large extent on the services of certain key management personnel, including our executive officers and other key employees, the loss of any of whom could have a material adverse effect on our operations. We have entered into employment agreements with each of S.P. Johnson IV, our President and Chief Executive Officer, Paul F. Boling, our Vice President and Chief Financial Officer, J. Bradley Fisher, our Vice President and Chief Operating Officer, Gregory E. Evans, our Vice President of Exploration and Richard H. Smith, our Vice President of Land. We do not maintain key-man life insurance with respect to any of our employees. Our success will be dependent on our ability to continue to employ and retain skilled technical personnel.

We may experience difficulty in achieving and managing future growth.

We have experienced growth in the past primarily through the expansion of our drilling program. Future growth may place strains on our financial, technical, operational and administrative resources and cause us to rely more on project partners and independent contractors, possibly negatively affecting our financial condition and results of operations. Our ability to grow will depend on a number of factors, including:

•  our ability to obtain leases or options on properties, including those for which we have 3-D seismic data;

•  our ability to acquire additional 3-D seismic data;

•  our ability to identify and acquire new exploratory prospects;

•  our ability to develop existing prospects;

•  our ability to continue to retain and attract skilled personnel;

•  our ability to maintain or enter into new relationships with project partners and independent contractors;

•  the results of our drilling program;

•  hydrocarbon prices; and

•  our access to capital.

We may not be successful in upgrading our technical, operations and administrative resources or in increasing our ability to internally provide certain of the services currently provided by outside sources, and we may not be able to maintain or enter into new relationships with project partners and independent contractors. Our inability to achieve or manage growth may adversely affect our financial condition and results of operations.

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We may continue to enter into derivative transactions to manage the price risks associated with our production. Our derivative transactions may result in our making cash payments or prevent us from benefiting from increases in prices for natural gas and oil.

Because natural gas and oil prices are unstable, we periodically enter into price-risk-management transactions such as swaps, collars, futures and options to reduce our exposure to price declines associated with a portion of our natural gas and oil production and thereby to achieve a more predictable cash flow. The use of these arrangements limits our ability to benefit from increases in the prices of natural gas and oil. Our derivative arrangements may apply to only a portion of our production, thereby providing only partial protection against declines in natural gas and oil prices. These arrangements may expose us to the risk of financial loss in certain circumstances, including instances in which production is less than expected, our customers fail to purchase contracted quantities of natural gas and oil or a sudden, unexpected event materially impacts natural gas or oil prices.

We have substantial capital requirements that, if not met, may hinder operations.

We have experienced and expect to continue to experience substantial capital needs as a result of our active exploration, development and acquisition programs. We expect that additional external financing will be required in the future to fund our growth. We may not be able to obtain additional financing, and financing under existing or new credit facilities may not be available in the future. Even if additional capital becomes available, it may not be on terms acceptable to us. Without additional capital resources, we may be forced to limit or defer our planned natural gas and oil exploration and development program and thereby adversely affect the recoverability and ultimate value of our natural gas and oil properties, in turn negatively affecting our business, financial condition and results of operations.

High demand for field services and equipment and the ability of suppliers to meet that demand may limit our ability to drill and produce our oil and natural gas properties.

Due to current industry demands, well service providers and related equipment and personnel are in short supply. This is causing escalating prices, delays in drilling and other exploration activities, the possibility of poor services coupled with potential damage to downhole reservoirs and personnel injuries. Such pressures will likely increase the actual cost of services, extend the time to secure such services and add costs for damages due to any accidents sustained from the overuse of equipment and inexperienced personnel.

Our credit facilities contain operating restrictions and financial covenants, and we may have difficulty obtaining additional credit.

Over the past few years, increases in commodity prices and proved reserve amounts and the resulting increase in our estimated discounted future net revenue have allowed us to increase our available borrowing amounts. In the future, commodity prices may decline, we may increase our borrowings or our borrowing base may be adjusted downward, thereby reducing our borrowing capacity. Our credit facilities are secured by a pledge of substantially all of our producing natural gas and oil properties and assets, are guaranteed by our subsidiaries CCBM, Inc. and CLLR, Inc. and contain covenants that limit additional borrowings, dividends, the incurrence of liens, investments, sales or pledges of assets, changes in control, repurchases or redemptions for cash of our common stock, speculative commodity transactions and other matters. The credit facilities also require that specified financial ratios be maintained. We may not be able to refinance our debt or obtain additional financing, particularly in view of the restrictions of our credit facilities on our ability to incur additional debt and the fact that substantially all of our assets are currently pledged to secure obligations under the credit

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facilities. The restrictions of our credit facilities and our difficulty in obtaining additional debt financing may have adverse consequences on our operations and financial results, including:

•  our ability to obtain financing for working capital, capital expenditures, our drilling program, purchases of new technology or other purposes may be impaired;

•  the covenants in our credit facilities that limit our ability to borrow additional funds and dispose of assets may affect our flexibility in planning for, and reacting to, changes in business conditions;

•  because our indebtedness is subject to variable interest rates, we are vulnerable to increases in interest rates;

•  any additional financing we obtain may be on unfavorable terms;

•  we may be required to use a substantial portion of our cash flow to make debt service payments, which will reduce the funds that would otherwise be available for operations and future business opportunities;

•  a substantial decrease in our operating cash flow or an increase in our expenses could make it difficult for us to meet debt service requirements and could require us to modify our operations, including by curtailing portions of our drilling program, selling assets, reducing our capital expenditures, refinancing all or a portion of our existing debt or obtaining additional financing; and

•  we may become more vulnerable to downturns in our business or the economy.

In addition, under the terms of our credit facilities, our borrowing base is subject to redeterminations at least quarterly based in part on prevailing natural gas and oil prices. In the event the amount outstanding exceeds the redetermined borrowing base, we could be forced to repay a portion of our borrowings. We may not have sufficient funds to make any required repayment. If we do not have sufficient funds and are otherwise unable to negotiate renewals of our borrowings or arrange new financing, we may have to sell a portion of our assets.

We may record ceiling limitation write-downs that would reduce our shareholders’ equity.

We use the full-cost method of accounting for investments in natural gas and oil properties. Accordingly, we capitalize all the direct costs of acquiring, exploring for and developing natural gas and oil properties. Under the full-cost accounting rules, the net capitalized cost of natural gas and oil properties may not exceed a “ceiling limit” that is based on the present value of estimated future net revenues from proved reserves, discounted at 10%, plus the lower of the cost or the fair market value of unproved properties. If net capitalized costs of natural gas and oil properties exceed the ceiling limit, we must charge the amount of the excess to operations through depreciation, depletion and amortization expense. This charge is called a “ceiling limitation write-down.” This charge does not impact cash flow from operating activities but does reduce our shareholders’ equity. The risk that we will be required to write down the carrying value of our natural gas and oil properties increases when natural gas and oil prices are low or volatile. In addition, write-downs would occur if we were to experience sufficient downward adjustments to our estimated proved reserves or the present value of estimated future net revenues, as further discussed above in “Our reserve data and estimated discounted future net cash flows are estimates based on assumptions that may be inaccurate and are based on existing economic and operating conditions that may change in the future.” Once incurred, a write-down of natural gas and oil properties is not reversible at a later date.

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We participate in oil and natural gas leases with third parties.

We may own less than 100% of the working interest in certain leases acquired by us, and other parties will own the remaining portion of the working interest. Financial risks are inherent in any operation where the cost of drilling, equipping, completing and operating wells is shared by more than one person. We could be held liable for the joint activity obligations of the other working interest owners such as nonpayment of costs and liabilities arising from the actions of the working interest owners. In the event other working interest owners do not pay their share of such costs, we would likely have to pay those costs, which could materially adversely affect our financial condition.

We may incur losses as a result of title deficiencies.

We purchase working and revenue interests in the natural gas and oil leasehold interests upon which we will perform our exploration activities from third parties or directly from the mineral fee owners. The existence of a material title deficiency can render a lease worthless and can adversely affect our results of operations and financial condition. Title insurance covering mineral leaseholds is not generally available and, in all instances, we forego the expense of retaining lawyers to examine the title to the mineral interest to be placed under lease or already placed under lease until the drilling block is assembled and ready to be drilled. As is customary in our industry, we rely upon the judgment of natural gas and oil lease brokers or independent landmen who perform the field work in examining records in the appropriate governmental offices and abstract facilities before attempting to acquire or place under lease a specific mineral interest. We, in some cases, perform curative work to correct deficiencies in the marketability of the title to us. The work might include obtaining affidavits of heirship or causing an estate to be administered. In cases involving more serious title problems, the amount paid for affected natural gas and oil leases can be generally lost, and the target area can become undrillable.

We have risks associated with our foreign operations.

We currently have international activities and we continue to evaluate and pursue new opportunities for international expansion in select areas. Ownership of property interests and production operations in areas outside the United States is subject to the various risks inherent in foreign operations. These risks may include:

•  currency restrictions and exchange rate fluctuations;

•  loss of revenue, property and equipment as a result of expropriation, nationalization, war or insurrection;

•  increases in taxes and governmental royalties;

•  renegotiation of contracts with governmental entities and quasi-governmental agencies;

•  changes in laws and policies governing operations of foreign-based companies;

•  labor problems; and

•  other uncertainties arising out of foreign government sovereignty over our international operations.

Our international operations also may be adversely affected by the laws and policies of the United States affecting foreign trade, taxation and investment. In addition, if a dispute arises with respect to our foreign operations, we may be subject to the exclusive jurisdiction of foreign courts or may not be successful in subjecting foreign persons to the jurisdiction of the courts of the United States.

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The threat and impact of terrorist attacks or similar hostilities may adversely impact our operations.

We cannot assess the extent of either the threat or the potential impact of future terrorist attacks on the energy industry in general, and on us in particular, either in the short-term or in the long-term. Uncertainty surrounding such hostilities may affect our operations in unpredictable ways, including the possibility that infrastructure facilities, including pipelines and gathering systems, production facilities, processing plants and refineries, could be targets of, or indirect casualties of, an act of terror or war.

Risks Related to Our Common Stock

The market price of our common stock is volatile.

The trading price of our common stock and the price at which we may sell common stock in the future are subject to large fluctuations in response to any of the following:

•  limited trading volume in our common stock;

•  quarterly variations in operating results;

•  our involvement in litigation;

•  general financial market conditions;

•  the prices of natural gas and oil;

•  announcements by us and our competitors;

•  our liquidity;

•  our ability to raise additional funds;

•  changes in government regulations; and

•  other events.

We do not anticipate paying dividends on our common stock in the near future.

We have not paid any dividends on our common stock in the past and do not intend to pay cash dividends on our common stock in the foreseeable future. We currently intend to retain any earnings for the future operation and development of our business, including exploration, development and acquisition activities. Any future dividend payments will be restricted by the terms of our credit facilities.

Certain anti-takeover provisions may affect your rights as a shareholder.

Our articles of incorporation authorize our board of directors to set the terms of and issue preferred stock without shareholder approval. Our board of directors could use the preferred stock as a means to delay, defer or prevent a takeover attempt that a shareholder might consider to be in our best interest. In addition, our credit facilities contain terms that may restrict our ability to enter into change of control transactions, including requirements to repay our credit facilities on a change in control. These provisions, along with specified provisions of the Texas Business Corporation Act and our articles of incorporation and bylaws, may discourage or impede transactions involving actual or potential changes in our control, including transactions that otherwise could involve payment of a premium over prevailing market prices to holders of our common stock.

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Sales of substantial amounts of shares of our common stock could cause the price of our common stock to decrease.

This prospectus covers the issuance by us of a substantial number of shares of our common stock. In addition, other investors may sell substantial number of shares of our common stock, as described in other filings under the Securities Act. These shares previously were not freely tradeable in the market. Our stock price may decrease due to the additional amount of shares available in the market.

Risks Related to Debt Securities

A holder’s right to receive payments on the debt securities is effectively subordinate to the rights of our existing and future secured creditors. Further, the guarantees of senior debt securities by the subsidiary guarantors are effectively subordinated to the subsidiary guarantors’ existing and future secured indebtedness.

Holders of our secured indebtedness and the secured indebtedness of the subsidiary guarantors will have claims that are prior to the claims of holders of senior debt securities to the extent of the value of the assets securing that other indebtedness. Notably, we are party to two credit facilities, which are secured by liens on substantially all of our assets and are guaranteed by our subsidiaries CCBM, Inc. and CLLR, Inc. The senior debt securities will be effectively subordinated to that secured indebtedness. In the event of any distribution or payment of our assets in any foreclosure, dissolution, winding-up, liquidation, reorganization or other bankruptcy proceeding, holders of secured indebtedness will have prior claim to our assets that constitute their collateral. Holders of the senior debt securities will participate ratably with all holders of our unsecured indebtedness that is deemed to be of the same class as the senior debt securities, and potentially with all of our other general creditors, based upon the respective amounts owed to each holder or creditor, in our remaining assets. In any of the foregoing events, we cannot assure you that there will be sufficient assets to pay amounts due on the senior debt securities. As a result, holders of senior debt securities may receive less, ratably, than holders of senior indebtedness.

Holders of debt securities may be structurally subordinated to the creditors of our subsidiaries.

We currently conduct our coalbed methane operations and hold interests in Pinnacle Gas Resources, Inc. through our wholly-owned subsidiary CCBM, Inc. We also hold a large portion of our interests in the Barnett Shale area in North Texas through our other wholly owned subsidiary, CLLR, Inc. Contractual provisions or laws, as well as our subsidiaries’ financial condition and operating requirements, may limit our ability to obtain cash from our subsidiaries that we use to pay our debt service obligations, including payments on the debt securities. In addition, holders of the debt securities will have a junior position to the claims of creditors, including trade creditors and tort claimants, of our subsidiaries to the extent that our subsidiaries do not guarantee such debt securities.

A holder’s right to receive payments on the debt securities could be adversely affected if any of our subsidiaries is not a guarantor of the debt securities and declares bankruptcy, liquidates or reorganizes.

If any of our subsidiaries is not a guarantor of the debt securities and declares bankruptcy, liquidates or reorganizes, holders of such subsidiary’s indebtedness and its trade creditors will generally be entitled to payment of their claims from the assets of the subsidiary before any assets are made available for distribution to us.

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Federal and state statutes allow courts, under specific circumstances, to void guarantees and require holders of the debt securities to return payments received from guarantors.

Under the federal bankruptcy law and comparable provisions of state fraudulent transfer laws, a guarantee could be voided or claims in respect of a guarantee could be subordinated to all other debts of the applicable guarantor if, among other things, the guarantor, at the time it incurred the indebtedness evidenced by its guarantee received less than reasonably equivalent value or fair consideration for the incurrence of such guarantee and either:

•  was insolvent or rendered insolvent by reason of such incurrence;

•  was engaged or about to engage in a business or transaction for which the guarantor’s remaining assets constituted unreasonably small capital; or

•  intended to incur, or believed that it would incur, debts beyond its ability to pay such debts as they mature.

In addition, any payment by that guarantor pursuant to its guarantee could be voided and required to be returned to the guarantor or to a fund for the benefit of the creditors of the guarantor.

The measures of insolvency for purposes of these fraudulent transfer laws will vary depending upon the law applied in any proceeding to determine whether a fraudulent transfer has occurred. Generally, a guarantor would be considered insolvent if, at the relevant time, the sum of its debts and other liabilities, including contingent liabilities, was greater than the sum of its assets at a fair valuation, and a guarantor that was generally not then paying its debts as they became due would be presumed to be insolvent.

We may incur additional debt ranking equal to the debt securities.

If we incur additional debt that ranks equally with the debt securities, the holders of that debt will be entitled to share ratably with the holders of the debt securities in any proceeds distributed in connection with any insolvency liquidation, reorganization, dissolution and other winding-up of us. This may have the effect of reducing the amount of proceeds paid to holders of debt securities.

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Forward-Looking Statements

This prospectus and the documents incorporated by reference in this prospectus contain statements concerning our expectations, beliefs, plans, objectives, goals, strategies, future events or performance and underlying assumptions and other statements that are not historical facts. These statements are “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995. You generally can identify our forward-looking statements by the words “anticipate,” “believe,” “budgeted,” “continue,” “could,” “estimate,” “expect,” “forecast,” “goal,” “intend,” “may,” “objective,” “plan,” “potential,” “predict,” “projection,” “scheduled,” “should,” “will” or other similar words. These forward-looking statements include, among others, statements regarding:

•  our growth strategies;

•  our ability to explore for and develop natural gas and oil resources successfully and economically;

•  our estimates of the timing and number of wells we expect to drill and other exploration activities;

•  anticipated trends in our business;

•  our future results of operations;

•  our liquidity and our ability to finance our exploration and development activities;

•  our capital expenditure program;

•  future market conditions in the oil and gas industry;

•  our ability to make and integrate acquisitions; and

•  the impact of governmental regulation.

More specifically, our forward-looking statements include, among others, statements relating to our schedule, targets, estimates or results of future drilling, including the number, timing and results of wells, budgeted wells, increases in wells, the timing and risk involved in drilling follow-up wells, expected working or net revenue interests, planned expenditures, prospects budgeted and other future capital expenditures, risk profile of oil and gas exploration, acquisition of 3-D seismic data (including number, timing and size of projects), planned evaluation of prospects, probability of prospects having oil and natural gas, expected production or reserves, increases in reserves, acreage, working capital requirements, hedging activities, the ability of expected sources of liquidity to implement our business strategy, future hiring, future exploration activity, production rates, potential drilling locations targeting coal seams, the outcome of legal challenges to new coalbed methane drilling permits in Montana, financing for our 2007 exploration and development program, all and any other statements regarding future operations, financial results, business plans and cash needs and other statements that are not historical facts.

Such statements involve risks and uncertainties, including, but not limited to, those relating to our dependence on our exploratory drilling activities, the volatility of oil and natural gas prices, the need to replace reserves depleted by production, operating risks of oil and natural gas operations, our dependence on our key personnel, factors that affect our ability to manage our growth and achieve our business strategy, risks relating to our limited operating history, technological changes, our significant capital requirements, the potential impact of government regulations, adverse regulatory determinations, including those related to coalbed methane drilling in Montana, litigation, competition, the uncertainty of reserve information and future net revenue estimates, property acquisition risks, industry partner issues, availability of equipment, weather and other factors detailed herein and in our other filings with the SEC.

We have based our forward-looking statements on our management’s beliefs and assumptions based on information available to our management at the time the statements are made. We caution you that

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assumptions, beliefs, expectations, intentions and projections about future events may and often do vary materially from actual results. Therefore, we cannot assure you that actual results will not differ materially from those expressed or implied by our forward-looking statements.

Some of the factors that could cause actual results to differ from those expressed or implied in forward-looking statements are described under “Risk Factors” in this prospectus and in any prospectus supplement and in the “Risk Factors” and other sections of the documents that we incorporate by reference into this prospectus, including our Annual Reports on Form 10-K and our Quarterly Reports on Form 10-Q and in our other reports filed with the SEC. Should one or more of these risks or uncertainties materialize, or should underlying assumptions prove incorrect, actual outcomes may vary materially from those indicated. All subsequent written and oral forward-looking statements attributable to us or persons acting on our behalf are expressly qualified in their entirety by reference to these risks and uncertainties. You should not place undue reliance on our forward-looking statements. Each forward-looking statement speaks only as of the date of the particular statement, and we undertake no duty to update any forward-looking statement.

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Use of Proceeds

Unless we inform you otherwise in the prospectus supplement, the net proceeds from the sale of the securities will be used for general corporate purposes, including:

•  repayment or refinancing of debt,

•  acquisitions,

•  working capital,

•  capital expenditures, and

•  repurchases and redemptions of securities.

Pending any specific application, we may initially invest funds in short-term marketable securities or apply them to the reduction of other short-term indebtedness.

Ratio of Earnings to Fixed Charges and Earnings to

Combined Fixed Charges and Preferred Stock Dividends

The following table presents our historical ratio of earnings to fixed charges and historical ratio of earnings to combined fixed charges and preferred stock dividends for each of the years in the five-year period ended December 31, 2006.

	Year Ended December 31,
	2006		2005		2004		2003		2002
Ratio of Earnings to Fixed Charges		1.97x		2.11x		5.18x		4.40x		2.45x
Ratio of Earnings to Combined Fixed Charges and Preferred Stock Dividends		1.97x		2.11x		4.81x		3.73x		2.22x

For purposes of this table, “earnings” consist of income before income taxes, extraordinary items and cumulative effect of accounting changes, plus fixed charges (excluding capitalized interest, but including amortization of amounts previously capitalized). “Fixed charges” consist of interest (including capitalized interest) on all debt, amortization of debt discounts and expenses incurred on issuance, and an estimate of the interest within rental expense.

Description of Debt Securities

Our debt securities covered by this prospectus will be our general unsecured obligations. We will issue senior debt securities on a senior unsecured basis under one or more separate indentures between us, one or both of our subsidiaries CCBM, Inc. and CLLR, Inc., if they are guarantors (the “Subsidiary Guarantors”), and a trustee that we will name in the prospectus supplement. We refer to any such indenture as a senior indenture. We will issue subordinated debt securities under one or more separate indentures between us, the Subsidiary Guarantors, if applicable, and a trustee that we will name in the prospectus supplement. We refer to any such indenture as a subordinated indenture. We refer to the senior indentures and the subordinated indentures collectively as the indentures. The indentures will be substantially identical, except for provisions relating to subordination. The senior debt securities will constitute senior debt and will rank equally with all of our unsecured and unsubordinated debt. The subordinated debt securities will be subordinated to, and thus have a junior position to, our senior debt (as defined with respect to the series of subordinated debt securities) and may rank equally with or senior or junior to our other subordinated debt that may be outstanding from time to time.

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We have summarized material provisions of the indentures, the debt securities and the guarantees below. This summary is not complete. We have filed the form of senior indenture and the form of subordinated indenture with the SEC as exhibits to the registration statement, and you should read the indentures for provisions that may be important to you. Please read “Where You Can Find More Information.”

In this summary description of the debt securities, unless we state otherwise or the context clearly indicates otherwise, all references to “us” or “we” mean Carrizo Oil & Gas, Inc. only.

Provisions applicable to each indenture

General.  The indentures do not limit the amount of debt securities that may be issued under that indenture, and do not limit the amount of other unsecured debt or securities that we may issue. We may issue debt securities under the indentures from time to time in one or more series, each in an amount authorized prior to issuance. The indentures also give us the ability to reopen a previous issue of a series of debt securities and issue additional debt securities of that series.

The indentures do not contain any covenants or other provisions designed to protect holders of the debt securities in the event we participate in a highly leveraged transaction or upon a change of control. The indentures also do not contain provisions that give holders the right to require us to repurchase their securities in the event of a decline in our credit ratings for any reason, including as a result of a takeover, recapitalization or similar restructuring or otherwise.

Terms.  The prospectus supplement relating to any series of debt securities being offered will include specific terms relating to the offering. These terms will include some or all of the following:

•  whether the debt securities will be senior or subordinated debt securities;

•  the title of the debt securities;

•  the total principal amount of the debt securities;

•  whether the debt securities will be issued in individual certificates to each holder or in the form of temporary or permanent global debt securities held by a depositary on behalf of holders;

•  the date or dates on which the principal of and any premium on the debt securities will be payable;

•  any interest rate, the date from which interest will accrue, interest payment dates and record dates for interest payments;

•  any right to extend or defer the interest payment periods and the duration of the extension;

•  whether and under what circumstances any additional amounts with respect to the debt securities will be payable;

•  whether debt securities are entitled to a guarantee of any Subsidiary Guarantors;

•  the place or places where payments on the debt securities will be payable;

•  any provisions for optional redemption or early repayment;

•  any sinking fund or other provisions that would require the redemption, purchase or repayment of debt securities;

•  the denominations in which the debt securities will be issued, if other than denominations of $1,000 and integral multiples thereof;

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•  whether payments on the debt securities will be payable in foreign currency or currency units or another form and whether payments will be payable by reference to any index or formula;

•  the portion of the principal amount of debt securities that will be payable if the maturity is accelerated, if other than the entire principal amount;

•  any additional means of defeasance of the debt securities, any additional conditions or limitations to defeasance of the debt securities or any changes to those conditions or limitations;

•  any changes or additions to the events of default or covenants described in this prospectus;

•  any restrictions or other provisions relating to the transfer or exchange of debt securities;

•  any terms for the conversion or exchange of the debt securities for other securities of ours or any other entity;

•  with respect to any subordinated indenture, any changes to the subordination provisions for the subordinated debt securities; and

•  any other terms of the debt securities not prohibited by the applicable indenture.

We may sell the debt securities at a discount, which may be substantial, below their stated principal amount. These debt securities may bear no interest or interest at a rate that at the time of issuance is below market rates. If we sell these debt securities, we will describe in the prospectus supplement any material United States federal income tax consequences and other special considerations.

If we sell any of the debt securities for any foreign currency or currency unit or if payments on the debt securities are payable in any foreign currency or currency unit, we will describe in the prospectus supplement the restrictions, elections, tax consequences, specific terms and other information relating to those debt securities and the foreign currency or currency unit.

Consolidation, Merger and Sale of Assets.  The indentures generally permit a consolidation or merger between us or any Subsidiary Guarantor and another entity. They also permit any Subsidiary Guarantor or us to sell, lease, convey, transfer or otherwise dispose of all or substantially all of our assets. We and any Subsidiary Guarantors have agreed, however, that we will not consolidate with or merge into any entity or sell, lease, convey, transfer or otherwise dispose of all or substantially all of our assets to any entity unless:

•  immediately after giving effect to the transaction, no default or event of default would occur and be continuing or would result from the transaction; and

•  if we or the Subsidiary Guarantor, as the case may be, are not the continuing entity, the resulting entity or transferee is organized and existing under the laws of any United States jurisdiction and assumes the due and punctual payments on the debt securities and the performance of our covenants and obligations under the indenture and the debt securities.

Upon any such consolidation or merger in which we are not the continuing entity or any such asset sale, lease, conveyance, transfer or disposition involving us, the resulting entity or transferee will be substituted for us under the applicable indenture and debt securities. In the case of an asset sale, conveyance, transfer or disposition other than a lease, we will be released from the applicable indenture.

Events of Default.  Unless we inform you otherwise in the applicable prospectus supplement, the following are events of default with respect to a series of debt securities:

•  failure to pay interest when due on that series of debt securities for 30 days;

•  failure to pay principal of or any premium on that series of debt securities when due;

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•  failure to make any sinking fund payment when required for that series for 30 days;

•  failure to comply with any covenant or agreement in that series of debt securities or the applicable indenture (other than an agreement or covenant that has been included in the indenture solely for the benefit of one or more other series of debt securities) for 90 days after written notice by the trustee or by the holders of at least 25% in principal amount of the outstanding debt securities issued under that indenture that are affected by that failure;

•  specified events involving bankruptcy, insolvency or reorganization of Carrizo Oil & Gas, Inc. or any Subsidiary Guarantor, if it is a guarantor with respect to that series of debt securities and it is a “significant subsidiary” as defined in Article I, Rule 1-02 of Regulation S-X promulgated under the Securities Act;

•  specified events involving the guarantees; and

•  any other event of default provided for that series of debt securities.

A default under one series of debt securities will not necessarily be a default under another series. The indentures provide that the trustee generally must mail notice of a default or event of default of which it has actual knowledge to the registered holders of the applicable debt securities within 90 days of occurrence. However, the trustee may withhold notice to the holders of the debt securities of any default or event of default (except in any payment on the debt securities) if the trustee considers it in the interest of the holders of the debt securities to do so.

If an event of default relating to certain events of bankruptcy, insolvency or reorganization occurs, the principal of and interest on all the debt securities issued under the applicable indenture will become immediately due and payable without any action on the part of the trustee or any holder. If any other event of default for any series of debt securities occurs and is continuing, the trustee or the holders of at least 25% in principal amount of the outstanding debt securities of the series affected by the default (or, in some cases, 25% in principal amount of all debt securities issued under the applicable indenture that are affected, voting as one class) may declare the principal of and all accrued and unpaid interest on those debt securities immediately due and payable. The holders of a majority in principal amount of the outstanding debt securities of the series affected by the event of default (or, in some cases, of all debt securities issued under the applicable indenture that are affected, voting as one class) may in some cases rescind this accelerated payment requirement.

A holder of a debt security of any series issued under an indenture may pursue any remedy under that indenture only if:

•  the holder gives the trustee written notice of a continuing event of default for that series;

•  the holders of at least 25% in principal amount of the outstanding debt securities of that series make a written request to the trustee to pursue the remedy;

•  the holders offer to the trustee indemnity satisfactory to the trustee;

•  the trustee fails to act for a period of 60 days after receipt of the request and offer of indemnity; and

•  during that 60-day period, the holders of a majority in principal amount of the debt securities of that series do not give the trustee a direction inconsistent with the request.

This provision does not, however, affect the right of a holder of a debt security to sue for enforcement of any overdue payment.

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In most cases, holders of a majority in principal amount of the outstanding debt securities of a series (or of all debt securities issued under the applicable indenture that are affected, voting as one class) may direct the time, method and place of:

•  with respect to debt securities of a series, conducting any proceeding for any remedy available to the trustee and exercising any trust or power conferred on the trustee relating to or arising as a result of specified events of default; or

•  with respect to all debt securities issued under the applicable indenture that are affected, conducting any proceeding for any remedy available to the trustee and exercising any trust or power conferred on the trustee relating to or arising other than as a result of such specified events of default.

The trustee, however, may refuse to follow any such direction that conflicts with law or the indentures, is unduly prejudicial to the rights of other holders of the debt securities, or would involve the trustee in personal liability. In addition, prior to acting at the direction of holders, the trustee will be entitled to be indemnified by those holders against any loss and expenses caused thereby.

The indentures require us to file each year with the trustee a written statement as to our compliance with the covenants contained in the applicable indenture.

Modification and Waiver.  Each indenture may be amended or supplemented if the holders of a majority in principal amount of the outstanding debt securities of all series issued under that indenture that are affected by the amendment or supplement (acting as one class) consent to it. Without the consent of the holder of each debt security issued under the indenture and affected, however, no modification to that indenture may:

•  reduce the amount of debt securities whose holders must consent to an amendment, supplement or waiver;

•  reduce the rate of or change the time for payment of interest on the debt security;

•  reduce the principal of the debt security or change its stated maturity;

•  reduce any premium payable on the redemption of the debt security or change the time at which the debt security may or must be redeemed;

•  change any obligation to pay additional amounts on the debt security;

•  make payments on the debt security payable in currency other than as originally stated in the debt security;

•  impair the holder’s right to institute suit for the enforcement of any payment on the debt security;

•  make any change in the percentage of principal amount of debt securities necessary to waive compliance with certain provisions of the indenture or to make any change in the provision related to modification;

•  with respect to the subordinated indenture, modify the provisions relating to the subordination of any subordinated debt security in a manner adverse to the holder of that security; or

•  waive a continuing default or event of default regarding any payment on the debt securities.

Each indenture may be amended or supplemented or any provision of that indenture may be waived without the consent of any holders of debt securities issued under that indenture in certain circumstances, including:

•  to cure any ambiguity, omission, defect or inconsistency;

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•  to provide for the assumption of our obligations under the indenture by a successor upon any merger or consolidation or asset sale, lease, conveyance, transfer or other disposition of all or substantially all of our assets, in each case as permitted under the indenture;

•  to provide for uncertificated debt securities in addition to or in place of certificated debt securities or to provide for bearer debt securities;

•  to provide any security for, any guarantees of or any additional obligors on any series of debt securities;

•  to comply with any requirement to effect or maintain the qualification of that indenture under the Trust Indenture Act of 1939, as amended (the “Trust Indenture Act”);

•  to add covenants that would benefit the holders of any debt securities or to surrender any rights we have under the indenture;

•  to add events of default with respect to any debt securities;

•  to make any change that does not adversely affect any outstanding debt securities of any series issued under that indenture in any material respect; and

•  to supplement the provisions of an indenture to permit or facilitate defeasance or discharge of securities that does not adversely affect any outstanding debt securities of any series issued under that indenture in any material respect.

The holders of a majority in principal amount of the outstanding debt securities of any series (or, in some cases, of all debt securities issued under the applicable indenture that are affected, voting as one class) may waive any existing or past default or event of default with respect to those debt securities. Those holders may not, however, waive any default or event of default in any payment on any debt security or compliance with a provision that cannot be amended or supplemented without the consent of each holder affected.

Defeasance.  When we use the term defeasance, we mean discharge from some or all of our obligations under an indenture. If any combination of funds or government securities are deposited with the trustee under an indenture sufficient to make payments on the debt securities of a series issued under that indenture on the dates those payments are due and payable, then, at our option, either of the following will occur:

•  we and any Subsidiary Guarantors will be discharged from our obligations with respect to the debt securities of that series (“legal defeasance”); or

•  we and any Subsidiary Guarantors will no longer have any obligation to comply with the consolidation, merger and sale of assets covenant and other specified covenants relating to the debt securities of that series, and the related events of default will no longer apply (“covenant defeasance”).

If a series of debt securities is defeased, the holders of the debt securities of the series affected will not be entitled to the benefits of the applicable indenture, except for obligations to register the transfer or exchange of debt securities, replace stolen, lost or mutilated debt securities or maintain paying agencies and hold moneys for payment in trust. In the case of covenant defeasance, our obligation to pay principal, premium and interest on the debt securities and, if applicable, a Subsidiary Guarantor’s guarantee of the payments, will also survive.

Unless we inform you otherwise in the prospectus supplement, we will be required to deliver to the trustee an opinion of counsel that the deposit and related defeasance would not cause the holders of the debt securities to recognize income, gain or loss for U.S. federal income tax purposes. If we elect legal

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defeasance, that opinion of counsel must be based upon a ruling from the U.S. Internal Revenue Service or a change in law to that effect.

Governing Law.  New York law will govern the indentures, the debt securities and the guarantees.

Trustee.  If an event of default occurs under an indenture and is continuing, the trustee under that indenture will be required to use the degree of care and skill of a prudent person in the conduct of that person’s own affairs. The trustee will become obligated to exercise any of its powers under that indenture at the request of any of the holders of any debt securities issued under that indenture only after those holders have offered the trustee indemnity satisfactory to it.

Each indenture contains limitations on the right of the trustee, if it becomes our creditor or, if applicable, a creditor of any Subsidiary Guarantor, to obtain payment of claims or to realize on certain property received for any such claim, as security or otherwise. The trustee is permitted to engage in other transactions with us or, if applicable, any Subsidiary Guarantor. If, however, it acquires any conflicting interest, it must eliminate that conflict or resign within 90 days after ascertaining that it has a conflicting interest and after the occurrence of a default under the applicable indenture, unless the default has been cured, waived or otherwise eliminated within the 90-day period.

Form, Exchange, Registration and Transfer.  The debt securities will be issued in registered form, without interest coupons. There will be no service charge for any registration of transfer or exchange of the debt securities. However, payment of any transfer tax or similar governmental charge payable for that registration may be required.

Debt securities of any series will be exchangeable for other debt securities of the same series, the same total principal amount and the same terms but in different authorized denominations in accordance with the applicable indenture. Holders may present debt securities for registration of transfer at the office of the security registrar or any transfer agent we designate. The security registrar or transfer agent will effect the transfer or exchange if its requirements and the requirements of the applicable indenture are met.

The trustee will be appointed as security registrar for the debt securities. If a prospectus supplement refers to any transfer agents we initially designate, we may at any time rescind that designation or approve a change in the location through which any transfer agent acts. We are required to maintain an office or agency for transfers and exchanges in each place of payment. We may at any time designate additional transfer agents for any series of debt securities.

In the case of any redemption, we will not be required to register the transfer or exchange of:

•  any debt security during a period beginning 15 business days prior to the mailing of any notice of redemption or mandatory offer to repurchase and ending on the close of business on the day of mailing of such notice; or

•  any debt security that has been called for redemption in whole or in part, except the unredeemed portion of any debt security being redeemed in part.

Payment and Paying Agent.  Unless we inform you otherwise in a prospectus supplement, payments on the debt securities will be made in U.S. dollars at the office of the trustee and any paying agent. At our option, however, payments may be made by wire transfer for global debt securities or by check mailed to the address of the person entitled to the payment as it appears in the security register. Unless we inform you otherwise in a prospectus supplement, interest payments will be made to the person in whose name the debt security is registered at the close of business on the record date for the interest payment.

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Unless we inform you otherwise in a prospectus supplement, the trustee under the applicable indenture will be designated as the paying agent for payments on debt securities issued under that indenture. We may at any time designate additional paying agents or rescind the designation of any paying agent or approve a change in the office through which any paying agent acts.

If the principal of or any premium or interest on debt securities of a series is payable on a day that is not a business day, the payment will be made on the next succeeding business day as if made on the date that the payment was due and no interest will accrue on that payment for the period from and after the due date to the date of that payment on the next succeeding business date. For these purposes, unless we inform you otherwise in a prospectus supplement, a “business day” is any day that is not a Saturday, a Sunday or a day on which banking institutions in any of New York, New York or Houston, Texas or a place of payment on the debt securities of that series is authorized or obligated by law, regulation or executive order to remain closed.

Subject to the requirements of any applicable abandoned property laws, the trustee and paying agent will pay to us upon written request any money held by them for payments on the debt securities that remains unclaimed for two years after the date upon which that payment has become due. After payment to us, holders entitled to the money must look to us for payment. In that case, all liability of the trustee or paying agent with respect to that money will cease.

Notices.  Any notice required by the indentures to be provided to holders of the debt securities will be given by mail to the registered holders at the addresses as they appear in the security register.

Replacement of Debt Securities.  We will replace any debt securities that become mutilated, destroyed, stolen or lost at the expense of the holder upon delivery to the trustee of the mutilated debt securities or evidence of the loss, theft or destruction satisfactory to us and the trustee. In the case of a lost, stolen or destroyed debt security, indemnity satisfactory to the trustee and us may be required at the expense of the holder of the debt securities before a replacement debt security will be issued.

Book-Entry Debt Securities.  The debt securities of a series may be issued in the form of one or more global debt securities that would be deposited with a depositary or its nominee identified in the prospectus supplement. Global debt securities may be issued in either temporary or permanent form. We will describe in the prospectus supplement the terms of any depositary arrangement and the rights and limitations of owners of beneficial interests in any global debt security.

Provisions applicable solely to subordinated debt securities

Subordination.  Under the subordinated indenture, payment of the principal of and any premium and interest on the subordinated debt securities will generally be subordinated and junior in right of payment to the prior payment in full of all Senior Debt, as described below. Unless we inform you otherwise in the prospectus supplement, we may not make any payment of principal of or any premium or interest on the subordinated debt securities if we fail to pay the principal, interest, premium or any other amounts on any Senior Debt when due.

The subordination does not affect our obligation, which is absolute and unconditional, to pay, when due, the principal of and any premium and interest on the subordinated debt securities. In addition, the subordination does not prevent the occurrence of any default under the subordinated indenture.

The subordinated indenture does not limit the amount of Senior Debt that we may incur. As a result of the subordination of the subordinated debt securities, if we become insolvent, holders of subordinated debt securities may receive less on a proportionate basis than other creditors.

Unless we inform you otherwise in a prospectus supplement, “Senior Debt” will mean all debt, including guarantees, of ours, unless the debt states that it is not senior to the subordinated debt

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securities or our other junior debt. Senior Debt with respect to a series of subordinated debt securities could include other series of debt securities issued under a subordinated indenture.

Guarantee

The Subsidiary Guarantors may fully and unconditionally guarantee on an unsecured basis the full and prompt payment of the principal of and any premium and interest on the debt securities issued by us when and as the payment becomes due and payable, whether at maturity or otherwise. The guarantee provides that in the event of a default in the payment of principal of or any premium or interest on a debt security, the holder of that debt security may institute legal proceedings directly against the applicable Subsidiary Guarantor to enforce the guarantee without first proceeding against us. If senior debt securities are so guaranteed, the guarantee will rank equally with all of the Subsidiary Guarantor’s other unsecured and unsubordinated debt from time to time outstanding and senior to any subordinated debt of the Subsidiary Guarantor. If subordinated debt securities are so guaranteed, the guarantee will be subordinated to all of our Subsidiary Guarantor’s other unsecured and unsubordinated debt from time to time outstanding.

The obligations of any Subsidiary Guarantor under the guarantee will be limited to the maximum amount that will not result in the obligations of the Subsidiary Guarantor under the guarantee constituting a fraudulent conveyance or fraudulent transfer under federal or state law, after giving effect to any other contingent and fixed liabilities of the Subsidiary Guarantor.

The guarantee may be released under certain circumstances. If we exercise our legal or covenant defeasance option with respect to debt securities of a particular series as described below in “— Defeasance and Discharge,” then any Subsidiary Guarantor will be released with respect to that series. Further, if no default has occurred and is continuing under the indentures, and to the extent not otherwise prohibited by the indentures, any Subsidiary Guarantor will be unconditionally released and discharged from the guarantee:

•  automatically upon any sale, exchange or transfer, whether by way of merger or otherwise, to any person that is not our affiliate, of all of our equity interests in the Subsidiary Guarantor;

•  automatically upon the merger of the Subsidiary Guarantor into us or any other Subsidiary Guarantor or the liquidation and dissolution of the Subsidiary Guarantor; or

•  following delivery of a written notice by us to the trustee, upon the release of all guarantees by the Subsidiary Guarantor of any debt of ours for borrowed money, except for any series of debt securities.

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Description of Capital Stock

The description of our capital stock in this section is a summary and is not intended to be complete. For a complete description of our capital stock, please read our amended and restated articles of incorporation and our amended and restated bylaws, which have been filed with the SEC.

General

Our authorized capital stock consists of (1) 40,000,000 shares of common stock, par value $0.01 per share, and (2) 10,000,000 shares of preferred stock, par value $0.01 per share. Approximately 26,001,692 shares of our common stock and no shares of preferred stock were outstanding as of April 13, 2007.

Common Stock

The holders of our common stock are entitled to one vote per share on all matters on which shareholders are permitted to vote. The holders of our common stock have no preemptive rights to purchase or subscribe for our securities, and our common stock is not convertible or subject to redemption by us.

Subject to the rights of the holders of any class of our capital stock having any preference or priority over our common stock, the holders of our common stock are entitled to dividends in such amounts as may be declared by our board of directors from time to time out of funds legally available for such payments and, if we are liquidated, dissolved or wound up, to a ratable share of any distribution to shareholders, after satisfaction of all our liabilities and the prior rights of any outstanding class of our preferred stock.

American Stock Transfer & Trust Company is the registrar and transfer agent for our common stock. Our common stock is listed on the Nasdaq Global Select Market under the symbol “CRZO.”

Preferred Stock

Our board of directors has the authority, without shareholder approval, to issue shares of preferred stock in one or more series, and to fix the number and terms of each such series. We have no present plan to issue shares of preferred stock.

The prospectus supplement relating to any series of preferred stock we are offering will include specific terms relating to the offering and the name of any transfer agent for that series. We will file the form of the preferred stock with the SEC before we issue any of it, and you should read it for provisions that may be important to you. The prospectus supplement will include some or all of the following terms:

•  the title of the preferred stock;

•  the maximum number of shares of the series;

•  the dividend rate or the method of calculating the dividend, the date from which dividends will accrue and whether dividends will be cumulative;

•  any liquidation preference;

•  any optional redemption provisions;

•  any sinking fund or other provisions that would obligate us to redeem or purchase the preferred stock;

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•  any terms for the conversion or exchange of the preferred stock for other securities of us or any other entity;

•  any voting rights; and

•  any other preferences and relative, participating, optional or other special rights or any qualifications, limitations or restrictions on the rights of the shares.

The issuance of shares of preferred stock could adversely affect the voting power of holders of our common stock, discourage an unsolicited acquisition proposal or make it more difficult for a third party to gain control of the Company. For instance, the issuance of a series of preferred stock might impede a business combination by including class voting rights that would enable the holder to block such a transaction or facilitate a business combination by including voting rights that would provide a required percentage vote of the shareholders. Although our board of directors is required to make any determination to issue preferred stock based on its judgment as to the best interests of our shareholders, the board could act in a manner that would discourage an acquisition attempt or other transaction that some of the shareholders might believe to be in their best interests or in which shareholders might receive a premium for their stock over the then market price of the stock. Our board of directors does not presently intend to seek shareholder approval prior to any issuance of currently authorized stock unless otherwise required by law or the rules of the Nasdaq Global Select Market.

Special Meetings

Our articles of incorporation provide that special meetings of our shareholders may be called only by the chairman of our board of directors, our president, a majority of our board of directors or by shareholders holding not less than 50% of our outstanding voting stock.

Voting

Our common stock does not have cumulative voting rights. Accordingly, holders of a majority of the total votes entitled to vote in an election of directors will be able to elect all of the directors.

Our articles of incorporation or Texas law requires the affirmative vote of holders of:

•  662/3% of the outstanding shares entitled to vote on the matter to approve any merger, consolidation or share exchange, any dissolution of the Company or certain dispositions of all or substantially all of our assets in which we do not continue to engage in a business or apply a portion of the consideration received in connection with the transaction to the conduct of a business in which we engage following the transaction; and

•  a majority of the outstanding shares entitled to vote on the matter to approve any amendment to our articles of incorporation or any other matter for which a shareholder vote is required by the Texas Business Corporation Act. If any class or series of shares is entitled to vote as a class with regard to these events, the vote required will be the affirmative vote of the holders of a majority of the outstanding shares within each class or series of shares entitled to vote thereon as a class and at least a majority of the outstanding shares of capital stock otherwise entitled to vote thereon.

Our bylaws provide that shareholders who wish to nominate directors or to bring business before a shareholders’ meeting must notify us and provide pertinent information at least 80 days before the meeting date, or within 10 days after public announcement pursuant to our bylaws of the meeting date, if the meeting date has not been publicly announced at least 90 days in advance.

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Our articles of incorporation and bylaws provide that no director may be removed from office except for cause and upon the affirmative vote of the holders of a majority of the votes entitled to be cast in the election of our directors. The following events constitute “cause”:

•  the director has been convicted, or is granted immunity to testify where another has been convicted, of a felony;

•  the director has been found by a court or by the affirmative vote of a majority of all other directors to be grossly negligent or guilty of willful misconduct in the performance of duties to us;

•  the director is adjudicated mentally incompetent; or

•  the director has been found by a court or by the affirmative vote of a majority of all other directors to have breached his duty of loyalty to us or our shareholders or to have engaged in a transaction with us from which the director derived an improper personal benefit.

Business Combination Law

We are subject to Part Thirteen (the “Business Combination Law”) of the Texas Business Corporation Act. In general, the Business Combination Law prevents an “affiliated shareholder” or its affiliates or associates from entering into or engaging in a “business combination” with an “issuing public corporation” during the three-year period immediately following the affiliated shareholder’s acquisition of shares unless:

•  before the date the person became an affiliated shareholder, the board of directors of the issuing public corporation approved the business combination or the acquisition of shares made by the affiliated shareholder on that date; or

•  not less than six months after the date the person became an affiliated shareholder, the business combination is approved by the affirmative vote of holders of at least two-thirds of the issuing public corporation’s outstanding voting shares not beneficially owned by the affiliated shareholder or its affiliates or associates.

For the purposes of the Business Combination Law, an “affiliated shareholder” is defined generally as a person who is or was within the preceding three-year period the beneficial owner of 20% or more of a corporation’s outstanding voting shares. A “business combination” is defined generally to include:

•  mergers or share exchanges;

•  dispositions of assets having an aggregate value equal to 10% or more of the market value of the assets or of the outstanding common stock representing 10% or more of the earning power or net income of the corporation;

•  certain issuances or transaction by the corporation that would increase the affiliated shareholder’s number of shares of the corporation;

•  certain liquidations or dissolutions; and

•  the receipt of tax, guarantee, loan or other financial benefits by an affiliated shareholder of the corporation.

An “issuing public corporation” is defined generally as a Texas corporation with 100 or more shareholders, any voting shares registered under the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or any voting shares qualified for trading in a national market system.

The Business Combination Law does not apply to a business combination of an issuing public corporation that elects not be governed thereby through either its original articles of incorporation or

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bylaws or by an amendment thereof. Our articles of incorporation and bylaws do not so provide, nor do we currently intend to make any such amendments.

In discharging the duties of a director under Texas law, a director, in considering the best interests of the Company, may consider the long-term as well as the short-term interests of the Company and our shareholders, including the possibility that those interests may be best served by our continued independence.

Limitation of Director Liability and Indemnification Arrangements

Our articles of incorporation contain a provision that limits the liability of our directors as permitted by the Texas Business Corporation Act. The provision eliminates the personal liability of a director to us and our shareholders for monetary damages for an act or omission in the director’s capacity as a director. The provision does not change the liability of a director for breach of his duty of loyalty to us or to our shareholders, for an act or omission not in good faith that involves intentional misconduct or a knowing violation of law, for an act or omission for which the liability of a director is expressly provided for by an applicable statute, or in respect of any transaction from which a director received an improper personal benefit. Pursuant to our articles of incorporation, the liability of directors will be further limited or eliminated without action by shareholders if Texas law is amended to further limit or eliminate the personal liability of directors.

Our bylaws provide for the indemnification of our officers and directors, and the advancement to them of expenses in connection with proceedings and claims, to the fullest extent permitted by the Texas Business Corporation Act. We have also entered into indemnification agreements with each of our directors and some of our officers that contractually provide for indemnification and expense advancement and include related provisions meant to facilitate the indemnitee’s receipt of such benefits. In addition, we have purchased directors’, and officers’ liability insurance policies for our directors and officers in the future. Our bylaws and these agreements with directors and officers provide for indemnification for amounts:

•  in respect of the deductibles for these insurance policies;

•  that exceed the liability limits of our insurance policies; and

•  that are available, were available or become available to us or are generally available to companies comparable to us but which our officers or directors determine is inadvisable for us to purchase, given the cost.

Such indemnification may be made even though our directors and officer would not otherwise be entitled to indemnification under other provisions of our bylaws or these agreements.

Description of Warrants

We may issue warrants to purchase debt securities, common stock, preferred stock, rights or other securities of the Company or any other entity or any combination of the foregoing. We may issue warrants independently or together with other securities. Warrants sold with other securities may be attached to or separate from the other securities. We will issue warrants under one or more warrant agreements between us and a warrant agent that we will name in the prospectus supplement.

The prospectus supplement relating to any warrants we are offering will include specific terms relating to the offering. We will file the form of any warrant agreement with the SEC, and you should

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read the warrant agreement for provisions that may be important to you. The prospectus supplement will include some or all of the following terms:

•  the title of the warrants;

•  the aggregate number of warrants offered;

•  the designation, number and terms of the debt securities, common stock, preferred stock, rights or other securities purchasable upon exercise of the warrants, and procedures by which the number of securities purchasable may be adjusted;

•  the exercise price of the warrants;

•  the dates or periods during which the warrants are exercisable;

•  the designation and terms of any securities with which the warrants are issued;

•  if the warrants are issued as a unit with another security, the date, if any, on and after which the warrants and the other security will be separately transferable;

•  if the exercise price is not payable in U.S. dollars, the foreign currency, currency unit or composite currency in which the exercise price is denominated;

•  any minimum or maximum amount of warrants that may be exercised at any one time; and

•  any terms, procedures and limitations relating to the transferability, exchange or exercise of the warrants.

Plan of Distribution

We may sell the securities in and outside the United States through underwriters or dealers, directly to purchasers or through agents. The prospectus supplement will include the following information:

•  the terms of the offering;

•  the names of any underwriters or agents;

•  the purchase price of the securities from us and, if the purchase price is not payable in U.S. dollars, the currency or composite currency in which the purchase price is payable;

•  the net proceeds to us from the sale of the securities;

•  any delayed delivery arrangements;

•  any underwriting discounts, commissions and other items constituting underwriters’ compensation;

•  the initial public offering price;

•  any discounts or concessions allowed or reallowed or paid to dealers; and

•  any commissions paid to agents.

Sale Through Underwriters or Dealers

If we use underwriters in the sale of securities, the underwriters will acquire the securities for their own account. The underwriters may resell the securities from time to time in one or more transactions, including negotiated transactions, at a fixed public offering price or at varying prices determined at the time of sale. Underwriters may offer securities to the public either through underwriting syndicates represented by one or more managing underwriters or directly by one or more firms acting as

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underwriters. Unless we inform you otherwise in the prospectus supplement, the obligations of the underwriters to purchase the securities will be subject to conditions, and the underwriters will be obligated to purchase all the securities if they purchase any of them. The underwriters may change from time to time any initial public offering price and any discounts or concessions allowed or reallowed or paid to dealers.

During and after an offering through underwriters, the underwriters may purchase and sell the securities in the open market. These transactions may include overallotment and stabilizing transactions and purchases to cover syndicate short positions created in connection with the offering. The underwriters may also impose a penalty bid, whereby selling concessions allowed to syndicate members or other broker-dealers for the offered securities sold for their account may be reclaimed by the syndicate if such offered securities are repurchased by the syndicate in stabilizing or covering transactions. These activities may stabilize, maintain or otherwise affect the market price of the offered securities, which may be higher than the price that might otherwise prevail in the open market. If commenced, these activities may be discontinued at any time.

If we use dealers in the sale of securities, we will sell the securities to them as principals. They may then resell those securities to the public at varying prices determined by the dealers at the time of resale. The dealers participating in any sale of the securities may be deemed to be underwriters within the meaning of the Securities Act with respect to any sale of those securities. We will include in the prospectus supplement the names of the dealers and the terms of the transaction.

Direct Sales and Sales Through Agents

We may sell the securities directly. In that event, no underwriters or agents would be involved. We may also sell the securities through agents we designate from time to time. In the prospectus supplement, we will name any agent involved in the offer or sale of the securities, and we will describe any commissions payable by us to the agent. Unless we inform you otherwise in the prospectus supplement, any agent will agree to use its reasonable best efforts to solicit purchases for the period of its appointment.

We may sell the 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 sale of those securities. We will describe the terms of any such sales in the prospectus supplement.

Delayed Delivery Contracts

If we so indicate in the prospectus supplement, we may authorize agents, underwriters or dealers to solicit offers from certain types of institutions to purchase securities from us at the public offering price under delayed delivery contracts. These contracts would provide for payment and delivery on a specified date in the future. The contracts would be subject only to those conditions described in the prospectus supplement. The prospectus supplement will describe the commission payable for solicitation of those contracts.

Remarketing

We may offer and sell any of the securities in connection with a remarketing upon their purchase, in accordance with a redemption or repayment by their terms or otherwise, by one or more remarketing firms acting as principals for their own accounts or as our agents. We will identify any remarketing firm, the terms of any remarketing agreement and the compensation to be paid to the remarketing firm in the prospectus supplement. Remarketing firms may be deemed underwriters under the Securities Act.

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Derivative Transactions

We 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 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 parties 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.

We or one of our affiliates may loan or pledge securities to a financial institution or other third party that in turn may sell the securities using this prospectus. Such financial institution or third party may transfer its short position to investors in our securities or in connection with a simultaneous offering of other securities offered by this prospectus or otherwise.

The third parties in any of the sale transactions described above will be underwriters and will be identified in the applicable prospectus supplement or in a post-effective amendment to the registration statement of which this prospectus forms a part.

General Information

We may have agreements with the agents, dealers and underwriters to indemnify them against civil liabilities, including liabilities under the Securities Act, or to contribute with respect to payments that the agents, dealers or underwriters may be required to make. Agents, dealers and underwriters may engage in transactions with us or perform services for us in the ordinary course of their businesses.

The securities may or may not be listed on a national securities exchange. We cannot assure you that there will be a market for the securities.

Legal Matters

The validity of the offered securities and other matters in connection with any offering of the securities will be passed upon for us by Baker Botts L.L.P., Houston, Texas, our outside counsel. Any underwriters will be advised about legal matters relating to any offering by their own legal counsel, which will be named in the related prospectus supplement.

Experts

Our consolidated financial statements and management’s assessment of the effectiveness of internal control over financial reporting (which is included in Management’s Report on Internal Control of Financial Reporting) for the years ended December 31, 2004, 2005 and 2006, incorporated by reference in this prospectus and registration statement, have been audited by Pannell Kerr Forster of Texas, P.C., independent registered public accounting firm, to the extent indicated in their reports thereon also incorporated by reference. Such consolidated financial statements and management’s assessment of the effectiveness of internal control over financial reporting have been so incorporated herein by reference in reliance on such reports given on the authority of said firm as experts in accounting and auditing.

The letter reports of Ryder Scott Company, Fairchild & Wells, Inc. and LaRoche Petroleum Consultants, Ltd., each independent consulting petroleum engineers, and certain information with respect to our oil and gas reserves derived from such reports and certain information with respect to our oil and gas reserves derived from the reports of DeGolyer and MacNaughton, independent consulting petroleum

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engineers, have been incorporated by reference into this prospectus upon the authority of each such firm as experts with respect to such matters covered in such reports and in giving such reports.

Where You Can Find More Information

We file annual, quarterly and current reports, proxy statements and other information with the SEC. You may read and copy this registration statement and any other documents we file at the SEC’s Public Reference Room at 100 F Street, N.E., Room 1580, Washington, D.C. 20549. Please call the SEC at 1-800-SEC-0330 for further information on the Public Reference Room. Our SEC filings are also available to the public at the SEC’s Internet site at http://www.sec.gov and our website at http://www.carrizo.net. Copies of these reports, proxy statements and other information concerning us can also be inspected at the offices of the Nasdaq Stock Market, Inc., which are located at 1735 K Street N.W., Washington, D.C. 20006. Information on our website or any other website is not incorporated by reference in this prospectus and does not constitute part of this prospectus.

This prospectus is part of a registration statement and, as permitted by SEC rules, does not contain all of the information included in the registration statement. Whenever a reference is made in this prospectus or any prospectus supplement to any of our contracts or other documents, the reference may not be complete and, for a copy of the contract or document, you should refer to the exhibits that are part of or incorporated by reference into the registration statement.

The SEC allows us to “incorporate by reference” into this prospectus the information we file with it, which means that we can disclose important information to you by referring you to those documents. Information incorporated by reference is considered to be part of this prospectus. Any statement contained in this prospectus or a document incorporated by reference in this prospectus will be deemed to be modified or superseded for purposes of this prospectus to the extent that a statement contained in this prospectus or in any other subsequently filed document that is incorporated by reference in this prospectus modifies or superseded the statement. Any statement so modified or superseded will not be deemed, except as so modified or superseded, to constitute a part of this prospectus. We incorporate by reference the documents listed below and future filings we make with the SEC under Section 13(a), 13(c), 14 or 15(d) of the Exchange Act (excluding any information “furnished” but not “filed,” unless we specifically provide that such “furnished” information is to be incorporated by reference) after the effectiveness of this registration statement and until the termination of offerings under this prospectus:

•  our Annual Report on Form 10-K for the year ended December 31, 2006;

•  our Current Report on Form 8-K filed on January 5, 2007; and

•  the description of our common stock in our Registration Statement on Form 8-A (Registration No. 000-22915) filed on July 31, 1997.

We will provide a copy of any and all of the information that is incorporated by reference in this prospectus to any person, including a beneficial owner, to whom a prospectus is delivered, without charge, upon written or oral request. You may obtain a copy of these filings by writing or telephoning:

Carrizo Oil & Gas, Inc.
Attention: Investor Relations
1000 Louisiana Street, Suite 1500
Houston, Texas 77002
(713) 328-1000.

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1,800,000 Shares

Carrizo Oil & Gas, Inc.

Common Stock

PRICE $41.40 PER SHARE

RBC Capital Markets

PROSPECTUS SUPPLEMENT

September 11, 2007