FORM 4
[X] Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).         	UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES
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                      	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 *

Buffalo Investor II, L.P.	2. Issuer Name and Ticker or Trading Symbol

SemGroup Corp [ SEMG ]	5. Relationship of Reporting Person(s) to Issuer (Check all applicable)

_____ Director                    __X__ 10% Owner
_____ Officer (give title below)    _____ Other (specify below)	
(Last)         (First)         (Middle)

C/O ALINDA CAPITAL PARTNERS,, 100 WEST PUTNAM AVENUE	3. Date of Earliest Transaction (MM/DD/YYYY)

9/16/2019		
(Street)

GREENWICH, CT 06830
(City)       (State)       (Zip)	4. If Amendment, Date Original Filed (MM/DD/YYYY)

9/18/2019 	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 Acquired, Disposed of, or Beneficially Owned	
1.Title of Security
(Instr. 3)	2. Trans. Date	2A. Deemed Execution Date, if any	3. Trans. Code
(Instr. 8)	4. Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4 and 5)	5. Amount of Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)	
			Code	V	Amount	(A) or (D)	Price				
Class A Common Stock 	9/16/2019 	 	S	  	3347077 (6)	D	$16.61 (5)	3999052 (6)	I 	See Footnotes (1)(3)(4)	
Class A Common Stock 	9/16/2019 	 	S	  	2295331 (6)	D	$16.61 (5)	2742440 (6)	I 	See Footnotes (2)(3)(4)	

Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)	
1. Title of Derivate Security
(Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Trans. Date	3A. Deemed Execution Date, if any	4. Trans. Code
(Instr. 8)	5. Number of Derivative Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4 and 5)	6. Date Exercisable and Expiration Date	7. Title and Amount of Securities Underlying Derivative Security
(Instr. 3 and 4)	8. Price of Derivative Security
(Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)	
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares					

Explanation of Responses:	
(1) 	These securities are directly held by Buffalo Investor I, L.P. Buffalo Investor I GP LLC is the general partner of Buffalo Investor I, L.P. Alinda GP II, L.P. is the sole member of Buffalo Investor I GP LLC. Alinda GP of GP II LLC is the general partner of Alinda GP II, L.P. Mr. Christopher W. Beale is the managing member of Alinda GP of GP II LLC.	
(2) 	These securities are directly held by Buffalo Investor II, L.P. Buffalo Investor II GP LLC is the general partner of Buffalo Investor II, L.P. Alinda Parallel Fund GP II, L.P. is the sole member of Buffalo Investor II GP, LLC. Alinda Parallel Fund GP II, Ltd is the general partner of Alinda Parallel Fund GP II, L.P. Mr. Christopher W. Beale is a director of Alinda Parallel Fund GP II, Ltd.	
(3) 	Due to the limitations of the electronic filing system certain Reporting Persons are filing a separate Form 4.	
(4) 	Each of the Reporting Persons (other than to the extent it directly holds securities reported herein) disclaims beneficial ownership of the securities held by the other Reporting Persons, except to the extent of such Reporting Person's pecuniary interest therein, and, pursuant to Rule 16a-1(a)(4) under the Securities Exchange Act of 1934, as amended (the "Exchange Act"), each of the Reporting Persons (other than to the extent it directly holds securities reported herein) states that the inclusion of these securities in this report shall not be deemed an admission of beneficial ownership of all of the reported securities for purposes of Section 16 or for any other purpose.	
(5) 	The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions ranging from $16.50 to $16.8975, inclusive. The Reporting Persons undertake to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price in the range set forth above.	
(6) 	This Form 4/A is being filed to amend and restate the original Form 4 filed by the Reporting Persons on September 18, 2019 (the "Original Form 4"). The total number of shares reported as sold in the Original Form 4 by the Reporting Persons was correct. This amendment corrects the allocation of shares sold by each of Buffalo Investor I, L.P. and Buffalo Investor II, L.P. on September 16, 2019.	

Reporting Owners	
Reporting Owner Name / Address	Relationships	
	Director	10% Owner	Officer	Other	
Buffalo Investor II, L.P.
C/O ALINDA CAPITAL PARTNERS,
100 WEST PUTNAM AVENUE
GREENWICH, CT 06830		X			
Buffalo Investor II GP, LLC
C/O ALINDA CAPITAL PARTNERS,
100 WEST PUTNAM AVENUE
GREENWICH, CT 06830		X			

Signatures		
BUFFALO INVESTOR II, L.P., By: BUFFALO INVESTOR II GP, LLC, its general partner, By: /s/ Christopher W. Beale, Name: Christopher W. Beale, Title: President		10/15/2019	
**Signature of Reporting Person		Date
	
BUFFALO INVESTOR II GP, LLC, By: /s/ Christopher W. Beale, Name: Christopher W. Beale, Title: President		10/15/2019	
**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 4(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.	
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB control number.