Exhibit 5.1

* Associated Firm

In our examination of the foregoing documents, we have assumed 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 photostatic or certified copies and the authenticity of the originals of such copies. As to various questions of material fact to this opinion, we have relied, to the extent we deemed reasonably appropriate, upon representations or certificates of officers of Reef Oil & Gas Partners, L.P., which will serve as the managing general partner of the Partnership, and upon documents, records and instruments furnished to us by the managing general partner, without independent verification of their accuracy.

In rendering the opinions herein provided, we have assumed that: (i) each subscriber will have paid the consideration specified in the subscriber’s Subscription Agreement, (ii) no event of withdrawal of the managing general partner has occurred, (iii) the Partnership Agreement will be duly executed by Reef Oil & Gas Partners, L.P., as managing general partner and on behalf of the subscribers pursuant to the power of attorney granted to it by the subscribers, and by Michael J. Mauceli, as initial limited partner, (iv) the certificate of formation on file with the Secretary of State of the State of Texas for the Partnership has not been amended, (v) a prospectus (or prospectus supplement) will have been prepared and filed with the SEC describing the Interests offered thereby, and (vi) all Interests will be issued and sold in the manner stated in the Registration Statement and the applicable prospectus.

Based on and subject to the foregoing and subject further to the assumptions, exceptions, and qualifications set forth herein stated, it is the opinion of this firm that when the Interests in the Partnership are sold to the subscribers and the subscribers are admitted as additional general partners or limited partners, as the case may be, to the Partnership that (a) such Interests will be legally issued and fully paid, and (b) the Interests will be non-assessable.

The opinions expressed above are limited in all respects to the laws of the State of Texas and the federal laws of the United States of America, each as in effect on the date hereof.

This opinion letter is limited to the matters stated herein, and no opinion is implied or may be inferred beyond the matters expressly stated. We hereby consent to the use of our opinion as herein set forth as an exhibit to the Registration Statement and to the use of our name under the caption “Legal Matters” in the prospectus forming a part of the Registration Statement. In giving this consent, we do not hereby admit that we come within the category of persons whose consent is required under Section 7 of the Securities Act or the rules and regulations of the SEC promulgated thereunder or Item 509 of Regulation S-K.

Sincerely,

/s/ Baker & McKenzie LLP

Baker & McKenzie LLP

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