Exhibit 5.1

CONSOL Energy Inc.

Consol Plaza

1800 Washington Road

Pittsburgh, PA 152411405

phone: 412/831-4517

Fax: 412/831-4930

e-mail: jerryrichey@consolenergy.com

Web: www.consolenergy.com

P. JEROME RICHEY

Senior Vice President and General Counsel

May 30, 2008

CONSOL Energy Inc.

CONSOL Plaza

1800 Washington Road

Pittsburgh, PA 15241-1421

Ladies and Gentlemen:

I have acted as counsel for CONSOL Energy Inc., a Delaware corporation (the “Company”) in connection with the preparation and filing of a registration statement on Form S-3 (File No. 333- ) (the “Registration Statement”) filed with the Securities and Exchange Commission pursuant to the Securities Act of 1933, as amended (the “Securities Act”), by the Company, as issuer, for the registration of the sale from time to time of (a) shares of common stock, par value $0.01 per share (the “Common Stock”) of the Company; (b) shares of preferred stock, par value $0.01 per share (the “Preferred Stock”) of the Company; (c) the Company’s senior debt securities and subordinated debt securities (collectively, the “Debt Securities”), which may be issued pursuant to a senior debt indenture, between the Company and a trustee to be named and qualified later trustee (the “Senior Debt Trustee”) (the “Senior Debt Indenture”) and a subordinated debt indenture between the Company and a trustee to be named and qualified later, as trustee (the “Subordinated Debt Trustee”) and, together with the Senior Debt Trustee, the “Trustees”) (the “Subordinated Indenture,” and together with the Senior Debt Indenture, the “Indentures”); (d) warrants of the Company (the “Warrants”), which may be issued pursuant to a warrant agreement between the Company and a designated Warrant Agent (the “Warrant Agreement”), (e) purchase contracts (the “Purchase Contracts”) which may be issued under one or more purchase contract agreements (each, a “Purchase Contract Agreement”) to be entered into between the Company and the purchase contract agent to be named therein (the “Purchase Contract Agent”); (f) units (the “Units”) to be issued under one or more unit agreements to be entered into among the Company, a bank or trust company, as unit agent (the “Unit Agent”), and the holders from time to time of the Units (each such unit agreement, a “Unit Agreement”) and (g) depositary shares (the “Depositary Shares”) to be issued under one or more depositary agreements to be entered into among the Company, a bank or trust company as depositary agent (the “Depositary Agent”) from time to time (each such depositary agreement, a "Depositary Agreement").

I, or those acting under my supervision, have examined originals or copies, certified or otherwise identified to my satisfaction, of such documents and records and have made such investigation of fact and such examination of law as I have deemed appropriate in order to enable me to render the opinions set forth herein. In conducting such investigation, I relied, without independent verification, upon certificates of officers of the Company, public

officials and other appropriate persons. In our examination, we have assumed the legal capacity of all natural persons, the genuineness of all signatures, the authenticity of all documents submitted to us as originals, the conformity to original documents of all documents submitted to us as certified or photostatic copies and the authenticity of the originals of such latter documents. As to any facts materials to the opinions expressed herein, we have, when such facts were not independently established, relied upon certificates of public officials and certificates, oaths, declarations and representations of the Company and of its officers, directors and other representatives.

Based upon the foregoing, I am of the opinion that:

1. When the necessary corporate action on the part of the Company has been taken to authorize the issuance and sale of such shares of Common Stock proposed to be sold by the Company, and when such shares of Common Stock are issued and delivered in accordance with the applicable underwriting or other agreement against payment therefor (in excess of par value thereof) or upon conversion or exercise of any Security offered under the Registration Statement (the “Offered Security”), in accordance with terms of such Offered Security or the instrument governing such Offered Security providing for such conversion or exercise as approved by the Board of Directors, for the consideration approved by the Board of Directors (which consideration is not less than the par value of the Common Stock), such shares of Common Stock will be validly issued, fully-paid and non-assessable.

2. Upon designation of the relative rights, preferences and limitations of any series of Preferred Stock by the Board of Directors of the Company and the proper filing with the Secretary of State of the State of Delaware of a Certificate of Designation relating to such series of Preferred Stock, all necessary corporate action on the part of the Company will have been taken to authorize the issuance and sale of such series of Preferred Stock proposed to be sold by the Company, and when such shares of Preferred Stock are issued and delivered in accordance with the applicable underwriting or other agreement against payment therefor (in excess of par value thereof) for the consideration approved by the Board of Directors, such shares of Preferred Stock will be validly issued, fully paid and non-assessable.

3. When the Indentures and any supplemental indenture to be entered into in connection with the issuance of any Debt Securities have been duly authorized, executed and delivered by the Trustees and the Company; the specific terms of a particular series of Debt Securities have been duly authorized and established in accordance with the Indenture; and such Debt Securities have been duly authorized, executed, authenticated, issued and delivered in accordance with the Indenture and the applicable underwriting or other agreement against payment therefor, such Debt Securities will constitute valid and binding obligations of the Company, enforceable in accordance with their terms, subject to applicable bankruptcy, insolvency and similar laws affecting creditors’ rights generally and equitable principles of general applicability.

4. When the Warrant Agreement to be entered into in connection with the issuance of any Warrants has been duly authorized, executed and delivered by the Warrant Agent and the Company; the specific terms of the Warrants have been duly authorized and established in accordance with the Warrant Agreement; and such Warrants have been duly authorized, executed, issued and delivered in accordance with the Warrant Agreement and the applicable underwriting or other agreement, such Warrants will constitute valid and binding obligations of the Company, enforceable in accordance with their terms, subject to applicable bankruptcy, insolvency and similar laws affecting creditors’ rights generally and equitable principles of general applicability.

5. When the Purchase Contract Agreement to be entered into in connection with the issuance of any Purchase Contracts has been duly authorized, executed and delivered by the Purchase Contract Agent and the Company; the specific terms of the Purchase Contracts have been duly authorized and established in accordance with the Purchase Contract Agreement; and such Purchase Contracts have been duly authorized, executed, issued and delivered in accordance with the Purchase Contract Agreement and the applicable underwriting or other agreement, such Purchase Contracts will constitute valid and binding obligations of the Company, enforceable in accordance with their terms, subject to applicable bankruptcy, insolvency and similar laws affecting creditors’ rights generally and equitable principles of general applicability.

6. When the Unit Agreement to be entered into in connection with the issuance of any Unit has been duly authorized, executed and delivered by the Unit Agent and the Company; the specific terms of the Units have been duly authorized and established in accordance with the Unit Agreement; and such Units have been duly

authorized, executed, issued and delivered in accordance with the Unit Agreement and the applicable underwriting or other agreement, such Units will constitute valid and binding obligations of the Company, enforceable in accordance with their terms, subject to applicable bankruptcy, insolvency and similar laws affecting creditors’ rights generally and equitable principles of general applicability.

7. When the Depositary Agreement with respect to the issuance of any Depositary Shares has been duly authorized, executed and delivered by the Depositary Agent and the Company and such Depositary Shares have been duly authorized, executed, issued and delivered in accordance with the Depositary Agreement, including the adoption of a Certificate relating to the Preferred Stock underlying such Depositary Shares and the filing of the Certificate with the Secretary of State of the State of Delaware, and the shares of Preferred Stock underlying such Depositary Shares have been deposited with a bank or trust company (which meets the requirements for the depositary set forth in the Registration Statement) under the applicable depositary agreement, and the depositary receipts representing the Depositary Shares have been duly executed, countersigned, registered and delivered in accordance with the Depositary Agreement and the applicable underwriting or other agreement approved by the Board of Directors upon payment of the consideration therefor provided for therein, the Depositary Shares will be validly issued.

In connection with the opinions expressed above, we have assumed that, at or prior to the time of the delivery of any such security, (i) the Board of Directors shall have duly established the terms of such security and duly authorized the issuance and sale of such security and such authorization shall not have been modified or rescinded; (ii) the Registration Statement shall have been declared effective and such effectiveness shall not have been terminated or rescinded; and (iii) there shall not have occurred any change in law affecting the validity or enforceability of such security. We have also assumed that none of the terms of any security to be established subsequent to the date hereof, nor the issuance and delivery of such security, nor the compliance by the Company with the terms of such security will violate any applicable law or public policy or will result in a violation of any provision of any instrument or agreement then binding upon the Company, or any restriction imposed by any court or governmental body having jurisdiction over the Company.

I express no opinion as to the law of any jurisdiction other than the laws of the State of New York, the General Corporation Law of the State of Delaware and the Commonwealth of Pennsylvania. The opinions set forth below are based on the laws, rules or regulations, as the case may be, in effect on the date hereof.

I consent to your filing of this opinion as an exhibit to the Registration Statement. By giving such consent, I do not hereby admit that I am within the category of persons whose consents are required under Section 7 of the Securities Act.

Very Truly Yours,

/s/ P. Jerome Richey, Esq.                            

P. Jerome Richey, Esq.

Senior Vice President and General Counsel