Initial Statement of Beneficial Ownership (3)

FORM 3	UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES	OMB APPROVAL OMB Number: 3235-0104 Estimated average burden hours per response... 0.5
	Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940

1. Name and Address of Reporting Person * Riverstone AMR Partners, L.P.	2. Date of Event Requiring Statement (MM/DD/YYYY) 2/9/2018	3. Issuer Name and Ticker or Trading Symbol Alta Mesa Resources, Inc. /DE [AMR]
(Last)        (First)        (Middle) C/O RIVERSTONE HOLDINGS LLC, 712 FIFTH AVENUE, 36TH FLOOR	4. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director                            ___ X ___ 10% Owner _____ Officer (give title below)          _____ Other (specify below)
(Street) NEW YORK, NY 10019        (City)              (State)              (Zip)	5. If Amendment, Date Original Filed (MM/DD/YYYY)	6. Individual or Joint/Group Filing (Check Applicable Line) ___ Form filed by One Reporting Person _ X _ Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Beneficially Owned
1.Title of Security (Instr. 4)	2. Amount of Securities Beneficially Owned (Instr. 4)	3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	4. Nature of Indirect Beneficial Ownership (Instr. 5)
Class A Common Stock	65776000	I	See footnotes   (1) (4) (5)
Class C Common Stock	20000000	I	See footnotes   (2) (4) (5)

Table II - Derivative Securities Beneficially Owned ( e.g. , puts, calls, warrants, options, convertible securities)
1. Title of Derivate Security (Instr. 4)	2. Date Exercisable and Expiration Date (MM/DD/YYYY)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Common Units	(2)	(2)	Class A Common Stock	20000000	(2)	I	See footnotes   (2) (4) (5)
Warrants (right to buy)	3/11/2018	2/9/2023	Class A Common Stock	28466666	$11.50	I	See footnotes   (3) (4) (5)

Explanation of Responses:
(1)	Includes 16,548,894 shares held of record by Silver Run Sponsor II, LLC ("Sponsor"), 18,522,000 shares held of record by Riverstone VI SR II Holdings, L.P. ("SR II Holdings"), 25,857,148 shares held by Riverstone AMR Partners, L.P. ("AMR Partners"), 1,720,243 shares held of record by Riverstone AMR Partners-U, LLC ("AMR Partners-U") and 3,127,715 shares held of record by Riverstone AMR Partners-T, L.P.
(2)	Held of record by Riverstone VI Alta Mesa Holdings, L.P. ("Riverstone Contributor" and, together with the Sponsor, SR II Holdings, AMR Partners, AMR Partners-U and AMR Partners-T, the "Riverstone Funds"). In connection with the closing of the Issuer's initial business combination (the "Initial Business Combination"), the Issuer issued Riverstone Contributor 20,000,000 shares of Class C Common Stock and caused SRII Opco, LP to issue an equal number of its common units (the "SRII Opco Common Units") to the Riverstone Contributor in exchange for certain assets of Riverstone Contributor. The SRII Opco Common Units may, at the option of Riverstone Contributor, be redeemed for shares of Class A Common Stock on a one-to-one basis at any time after 180 days after the closing of the Initial Business Combination and have no expiration date. Upon redemption, an equal number of shares of Class C Common Stock will be cancelled.
(3)	Includes 9,716,012 warrants held of record by Sponsor, 13,333,333 warrants held of record by SR II Holdings, 4,561,992 warrants held by AMR Partners, 303,504 warrants held of record by AMR Partners-U and 551,825 warrants held of record by AMR Partners-T. Of these, 15,133,333 warrants were purchased simultaneous with the closing of the Issuer's initial public offering on March 29, 2017, and 13,333,333 warrants were issued pursuant to a forward purchase agreement dated as of March 17, 2017. The warrants became exercisable after the completion of the Initial Business Combination, which occurred on February 9, 2018.
(4)	David M. Leuschen and Pierre F. Lapeyre, Jr. are the members of Riverstone Management Group, L.L.C. ("Riverstone Management"), which is the general partner of Riverstone/Gower Mgmt Co Holdings, L.P. ("Riverstone/Gower"), which is the sole member of Riverstone Holdings LLC ("Holdings"), which is the sole shareholder of Riverstone Energy GP VI Corp, which is the managing member of Riverstone Energy GP VI, LLC ("Riverstone Energy GP") which is the general partner of Riverstone Energy Partners VI, L.P., which is the general partner of AMR Partners, the manager of AMR Partners-U and the managing member of Riverstone Energy VI Holdings GP, LLC, which is the general partner of each of the Riverstone Contributor and SR II Holdings, which is the sole and managing member of Sponsor. Riverstone Energy GP is also the sole member of Riverstone Energy Partners VI (Non-U.S.), LLC, which is the general partner of AMR Partners-T, L.P.
(5)	Riverstone Energy GP is managed by a managing committee consisting of Pierre F. Lapeyre, Jr., David M. Leuschen, E. Bartow Jones, N. John Lancaster, Baran Tekkora and Robert M. Tichio. As such, each of Riverstone Energy GP, Riverstone Energy GP VI Corp, Holdings, Riverstone/Gower, Riverstone Management, Mr. Leuschen and Mr. Lapeyre may be deemed to have or share beneficial ownership of the securities held directly by the Riverstone Funds. Each such entity or person disclaims any such beneficial ownership of such securities except to the extent of their pecuniary interest therein, and this report shall not be deemed an admission that the reporting person is the beneficial owner of the securities for purposes of Section 16 or for any other purpose.

Reporting Owners
Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
Riverstone AMR Partners, L.P. C/O RIVERSTONE HOLDINGS LLC 712 FIFTH AVENUE, 36TH FLOOR NEW YORK, NY 10019		X
Riverstone AMR Partners-U, LLC C/O RIVERSTONE HOLDINGS LLC 712 FIFTH AVENUE, 36TH FLOOR NEW YORK, NY 10019		X
Riverstone AMR Partners-T, L.P. C/O RIVERSTONE HOLDINGS LLC 712 FIFTH AVENUE, 36TH FLOOR NEW YORK, NY 10019		X
Riverstone Energy Partners VI (Non-U.S.), LLC C/O RIVERSTONE HOLDINGS LLC 712 FIFTH AVENUE, 36TH FLOOR NEW YORK, NY 10019		X
Riverstone/Gower Mgmt Co Holdings, L.P. C/O RIVERSTONE HOLDINGS LLC 712 FIFTH AVENUE, 36TH FLOOR NEW YORK, NY 10019		X
Riverstone Management Group, L.L.C. C/O RIVERSTONE HOLDINGS LLC 712 FIFTH AVENUE, 36TH FLOOR NEW YORK, NY 10019		X
Riverstone VI Alta Mesa Holdings, L.P. C/O RIVERSTONE HOLDINGS LLC 712 FIFTH AVENUE, 36TH FLOOR NEW YORK, NY 10019		X

Signatures
Riverstone AMR Partners, LLC By: Riverstone Energy Partners VI, L.P., its manager By: Riverstone Energy GP VI, LLC, its general partner By: /s/ Thomas J. Walker, Managing Director		2/14/2018
** Signature of Reporting Person		Date
Riverstone AMR Partners-U, LLC By: Riverstone Energy Partners VI, L.P., its manager By: Riverstone Energy GP VI, LLC, its general partner By: /s/ Thomas J. Walker, Managing Director		2/14/2018
** Signature of Reporting Person		Date
Riverstone AMR Partners-T, L.P. By: Riverstone Energy Partners VI (Non-U.S.), LLC, its general partner By: Riverstone Energy GP VI, LLC, its sole member By: /s/ Thomas J. Walker, Managing Director		2/14/2018
** Signature of Reporting Person		Date
Riverstone VI Alta Mesa Holdings, L.P. By: Riverstone Energy GP VI, LLC, its general partner By: /s/ Thomas J. Walker, Managing Director		2/14/2018
** Signature of Reporting Person		Date
Riverstone Energy Partners VI (Non-U.S.), LLC By: Riverstone Energy GP VI, LLC, its sole member By: /s/ Thomas J. Walker, Managing Director		2/14/2018
** Signature of Reporting Person		Date
Riverstone/Gower Mgmt Co Holdings, L.P. By: Riverstone Management Group, L.L.C., its general partner By: /s/ Thomas J. Walker, Managing Director		2/14/2018
** Signature of Reporting Person		Date
By: Riverstone Management Group, L.L.C. By: /s/ Thomas J. Walker, Managing Director		2/14/2018
** Signature of Reporting Person		Date

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
*	If the form is filed by more than one reporting person, see Instruction 5(b)(v).
**	Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note:	File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
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