WES

SEC source: 0001423902-26-000009 · wk-form4_1771021244.xml · nonDerivative · entry 7

Holderman Daniel P. · CIK 0001942513 · SVP & Chief Operating Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 82,756

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0001423902-26-000009 · wk-form4_1771021244.xml · nonDerivative · entry 6

Holderman Daniel P. · CIK 0001942513 · SVP & Chief Operating Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 57,440

SEC source: 0001423902-26-000009 · wk-form4_1771021244.xml · nonDerivative · entry 5

Holderman Daniel P. · CIK 0001942513 · SVP & Chief Operating Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 61,379

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0001423902-26-000009 · wk-form4_1771021244.xml · nonDerivative · entry 4

Holderman Daniel P. · CIK 0001942513 · SVP & Chief Operating Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 51,370

SEC source: 0001423902-26-000009 · wk-form4_1771021244.xml · nonDerivative · entry 3

Holderman Daniel P. · CIK 0001942513 · SVP & Chief Operating Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 57,249

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0001423902-26-000009 · wk-form4_1771021244.xml · nonDerivative · entry 2

Holderman Daniel P. · CIK 0001942513 · SVP & Chief Operating Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 42,309

SEC source: 0001423902-26-000009 · wk-form4_1771021244.xml · nonDerivative · entry 1

Holderman Daniel P. · CIK 0001942513 · SVP & Chief Operating Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 46,567

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0001423902-26-000006 · wk-form4_1771021053.xml · derivative · entry 22

Shults Kristen S. · CIK 0001925496 · SVP & Chief Financial Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 17,710

Underlying: Common Units representing limited partner interests · 17,710 shares

Expires 2029-02-12

F4 · derivative.exercise_price: Each performance-based unit represents the right to receive, following vesting, between 0% and 200% of one WES Common Unit (or cash equivalent) based upon the achievement of pre-established performance metrics over a 3-year performance period.

SEC source: 0001423902-26-000006 · wk-form4_1771021053.xml · derivative · entry 21

Shults Kristen S. · CIK 0001925496 · SVP & Chief Financial Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 17,710

Underlying: Common Units representing limited partner interests · 17,710 shares

Expires 2029-02-12

F4 · derivative.exercise_price: Each performance-based unit represents the right to receive, following vesting, between 0% and 200% of one WES Common Unit (or cash equivalent) based upon the achievement of pre-established performance metrics over a 3-year performance period.

SEC source: 0001423902-26-000006 · wk-form4_1771021053.xml · derivative · entry 20

Shults Kristen S. · CIK 0001925496 · SVP & Chief Financial Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 35,419

Underlying: Common Units representing limited partner interests · 35,419 shares

Expires 2029-02-12

F1 · derivative.exercise_price: Each Phantom Unit is the economic equivalent of one WES Common Unit representing limited partnership interests, and upon vesting, will entitle the holder to receive a common unit or, at the discretion of the Board of Directors of the General Partner, cash equal to the Fair Market Value of a Common Unit.

F2 · derivative.exercise_date: These Phantom Units vest ratably over a three-year period on February 12th of each year, and will pay distribution equivalent rights in cash on a current basis.

SEC source: 0001423902-26-000006 · wk-form4_1771021053.xml · derivative · entry 17

Shults Kristen S. · CIK 0001925496 · SVP & Chief Financial Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 20,017

Underlying: Common Units representing limited partner interests · 10,009 shares

Expires 2028-02-12

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: Each Phantom Unit is the economic equivalent of one WES Common Unit representing limited partnership interests, and upon vesting, will entitle the holder to receive a common unit or, at the discretion of the Board of Directors of the General Partner, cash equal to the Fair Market Value of a Common Unit.

F2 · derivative.exercise_date: These Phantom Units vest ratably over a three-year period on February 12th of each year, and will pay distribution equivalent rights in cash on a current basis.

SEC source: 0001423902-26-000006 · wk-form4_1771021053.xml · derivative · entry 14

Shults Kristen S. · CIK 0001925496 · SVP & Chief Financial Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 14,939

Underlying: Common Units representing limited partner interests · 14,940 shares

Expires 2027-02-12

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: Each Phantom Unit is the economic equivalent of one WES Common Unit representing limited partnership interests, and upon vesting, will entitle the holder to receive a common unit or, at the discretion of the Board of Directors of the General Partner, cash equal to the Fair Market Value of a Common Unit.

F2 · derivative.exercise_date: These Phantom Units vest ratably over a three-year period on February 12th of each year, and will pay distribution equivalent rights in cash on a current basis.

SEC source: 0001423902-26-000006 · wk-form4_1771021053.xml · derivative · entry 13

Shults Kristen S. · CIK 0001925496 · SVP & Chief Financial Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Units representing limited partner interests · 30,704 shares

Expires 2026-02-12

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F3 · derivative.exercise_price: Each performance-based unit represents the right to receive, following vesting, between 0% and 200% of one WES Common Unit based upon the achievement of pre-established performance metrics over a 3-year performance period.

SEC source: 0001423902-26-000006 · wk-form4_1771021053.xml · derivative · entry 12

Shults Kristen S. · CIK 0001925496 · SVP & Chief Financial Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Units representing limited partner interests · 25,316 shares

Expires 2026-02-12

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F3 · derivative.exercise_price: Each performance-based unit represents the right to receive, following vesting, between 0% and 200% of one WES Common Unit based upon the achievement of pre-established performance metrics over a 3-year performance period.

SEC source: 0001423902-26-000006 · wk-form4_1771021053.xml · derivative · entry 11

Shults Kristen S. · CIK 0001925496 · SVP & Chief Financial Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Units representing limited partner interests · 10,819 shares

Expires 2026-02-12

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: Each Phantom Unit is the economic equivalent of one WES Common Unit representing limited partnership interests, and upon vesting, will entitle the holder to receive a common unit or, at the discretion of the Board of Directors of the General Partner, cash equal to the Fair Market Value of a Common Unit.

F2 · derivative.exercise_date: These Phantom Units vest ratably over a three-year period on February 12th of each year, and will pay distribution equivalent rights in cash on a current basis.

SEC source: 0001423902-26-000006 · wk-form4_1771021053.xml · nonDerivative · entry 10

Shults Kristen S. · CIK 0001925496 · SVP & Chief Financial Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 143,752

SEC source: 0001423902-26-000006 · wk-form4_1771021053.xml · nonDerivative · entry 9

Shults Kristen S. · CIK 0001925496 · SVP & Chief Financial Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 155,879

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0001423902-26-000006 · wk-form4_1771021053.xml · nonDerivative · entry 8

Shults Kristen S. · CIK 0001925496 · SVP & Chief Financial Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 125,175

SEC source: 0001423902-26-000006 · wk-form4_1771021053.xml · nonDerivative · entry 7

Shults Kristen S. · CIK 0001925496 · SVP & Chief Financial Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 135,137

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0001423902-26-000006 · wk-form4_1771021053.xml · nonDerivative · entry 6

Shults Kristen S. · CIK 0001925496 · SVP & Chief Financial Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 109,821

SEC source: 0001423902-26-000006 · wk-form4_1771021053.xml · nonDerivative · entry 5

Shults Kristen S. · CIK 0001925496 · SVP & Chief Financial Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 113,760

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0001423902-26-000006 · wk-form4_1771021053.xml · nonDerivative · entry 4

Shults Kristen S. · CIK 0001925496 · SVP & Chief Financial Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 103,751

SEC source: 0001423902-26-000006 · wk-form4_1771021053.xml · nonDerivative · entry 3

Shults Kristen S. · CIK 0001925496 · SVP & Chief Financial Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 109,630

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0001423902-26-000006 · wk-form4_1771021053.xml · nonDerivative · entry 2

Shults Kristen S. · CIK 0001925496 · SVP & Chief Financial Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 94,690

SEC source: 0001423902-26-000006 · wk-form4_1771021053.xml · nonDerivative · entry 1

Shults Kristen S. · CIK 0001925496 · SVP & Chief Financial Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 98,948

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0001423902-26-000007 · wk-form4_1771021103.xml · derivative · entry 22

Green Catherine A. · CIK 0001791874 · SVP & Chief Accounting Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 11,806

Underlying: Common Units representing limited partner interests · 11,806 shares

Expires 2029-02-12

F4 · derivative.exercise_price: Each performance-based unit represents the right to receive, following vesting, between 0% and 200% of one WES Common Unit (or cash equivalent) based upon the achievement of pre-established performance metrics over a 3-year performance period.

SEC source: 0001423902-26-000007 · wk-form4_1771021103.xml · derivative · entry 21

Green Catherine A. · CIK 0001791874 · SVP & Chief Accounting Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 11,806

Underlying: Common Units representing limited partner interests · 11,806 shares

Expires 2029-02-12

F4 · derivative.exercise_price: Each performance-based unit represents the right to receive, following vesting, between 0% and 200% of one WES Common Unit (or cash equivalent) based upon the achievement of pre-established performance metrics over a 3-year performance period.

SEC source: 0001423902-26-000007 · wk-form4_1771021103.xml · derivative · entry 20

Green Catherine A. · CIK 0001791874 · SVP & Chief Accounting Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 23,613

Underlying: Common Units representing limited partner interests · 23,613 shares

Expires 2029-02-12

F1 · derivative.exercise_price: Each Phantom Unit is the economic equivalent of one WES Common Unit representing limited partnership interests, and upon vesting, will entitle the holder to receive a common unit or, at the discretion of the Board of Directors of the General Partner, cash equal to the Fair Market Value of a Common Unit.

F2 · derivative.exercise_date: These Phantom Units vest ratably over a three-year period on February 12th of each year, and will pay distribution equivalent rights in cash on a current basis.

SEC source: 0001423902-26-000007 · wk-form4_1771021103.xml · derivative · entry 17

Green Catherine A. · CIK 0001791874 · SVP & Chief Accounting Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 16,013

Underlying: Common Units representing limited partner interests · 8,008 shares

Expires 2028-02-12

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: Each Phantom Unit is the economic equivalent of one WES Common Unit representing limited partnership interests, and upon vesting, will entitle the holder to receive a common unit or, at the discretion of the Board of Directors of the General Partner, cash equal to the Fair Market Value of a Common Unit.

F2 · derivative.exercise_date: These Phantom Units vest ratably over a three-year period on February 12th of each year, and will pay distribution equivalent rights in cash on a current basis.

SEC source: 0001423902-26-000007 · wk-form4_1771021103.xml · derivative · entry 14

Green Catherine A. · CIK 0001791874 · SVP & Chief Accounting Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 11,951

Underlying: Common Units representing limited partner interests · 11,952 shares

Expires 2027-02-12

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: Each Phantom Unit is the economic equivalent of one WES Common Unit representing limited partnership interests, and upon vesting, will entitle the holder to receive a common unit or, at the discretion of the Board of Directors of the General Partner, cash equal to the Fair Market Value of a Common Unit.

F2 · derivative.exercise_date: These Phantom Units vest ratably over a three-year period on February 12th of each year, and will pay distribution equivalent rights in cash on a current basis.

SEC source: 0001423902-26-000007 · wk-form4_1771021103.xml · derivative · entry 13

Green Catherine A. · CIK 0001791874 · SVP & Chief Accounting Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Units representing limited partner interests · 19,916 shares

Expires 2026-02-12

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F3 · derivative.exercise_price: Each performance-based unit represents the right to receive, following vesting, between 0% and 200% of one WES Common Unit based upon the achievement of pre-established performance metrics over a 3-year performance period.

SEC source: 0001423902-26-000007 · wk-form4_1771021103.xml · derivative · entry 12

Green Catherine A. · CIK 0001791874 · SVP & Chief Accounting Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Units representing limited partner interests · 16,421 shares

Expires 2026-02-12

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F3 · derivative.exercise_price: Each performance-based unit represents the right to receive, following vesting, between 0% and 200% of one WES Common Unit based upon the achievement of pre-established performance metrics over a 3-year performance period.

SEC source: 0001423902-26-000007 · wk-form4_1771021103.xml · derivative · entry 11

Green Catherine A. · CIK 0001791874 · SVP & Chief Accounting Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Units representing limited partner interests · 7,018 shares

Expires 2026-02-12

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: Each Phantom Unit is the economic equivalent of one WES Common Unit representing limited partnership interests, and upon vesting, will entitle the holder to receive a common unit or, at the discretion of the Board of Directors of the General Partner, cash equal to the Fair Market Value of a Common Unit.

F2 · derivative.exercise_date: These Phantom Units vest ratably over a three-year period on February 12th of each year, and will pay distribution equivalent rights in cash on a current basis.

SEC source: 0001423902-26-000007 · wk-form4_1771021103.xml · nonDerivative · entry 10

Green Catherine A. · CIK 0001791874 · SVP & Chief Accounting Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 115,036

SEC source: 0001423902-26-000007 · wk-form4_1771021103.xml · nonDerivative · entry 9

Green Catherine A. · CIK 0001791874 · SVP & Chief Accounting Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 122,950

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0001423902-26-000007 · wk-form4_1771021103.xml · nonDerivative · entry 8

Green Catherine A. · CIK 0001791874 · SVP & Chief Accounting Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 103,034

SEC source: 0001423902-26-000007 · wk-form4_1771021103.xml · nonDerivative · entry 7

Green Catherine A. · CIK 0001791874 · SVP & Chief Accounting Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 109,496

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0001423902-26-000007 · wk-form4_1771021103.xml · nonDerivative · entry 6

Green Catherine A. · CIK 0001791874 · SVP & Chief Accounting Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 93,075

SEC source: 0001423902-26-000007 · wk-form4_1771021103.xml · nonDerivative · entry 5

Green Catherine A. · CIK 0001791874 · SVP & Chief Accounting Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 96,227

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0001423902-26-000007 · wk-form4_1771021103.xml · nonDerivative · entry 4

Green Catherine A. · CIK 0001791874 · SVP & Chief Accounting Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 88,219

SEC source: 0001423902-26-000007 · wk-form4_1771021103.xml · nonDerivative · entry 3

Green Catherine A. · CIK 0001791874 · SVP & Chief Accounting Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 92,923

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0001423902-26-000007 · wk-form4_1771021103.xml · nonDerivative · entry 2

Green Catherine A. · CIK 0001791874 · SVP & Chief Accounting Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 80,971

SEC source: 0001423902-26-000007 · wk-form4_1771021103.xml · nonDerivative · entry 1

Green Catherine A. · CIK 0001791874 · SVP & Chief Accounting Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 83,733

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0001423902-26-000031 · wk-form4a_1771536563.xml · nonDerivative · entry 1

Dial Christopher B. · CIK 0001729009 · SVP, GC and Secretary

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 225,015

F1 · kind: Original transaction code was S and should have been F.

SEC source: 0001140361-26-003924 · form4.xml · nonDerivative · entry 1

OCCIDENTAL PETROLEUM CORP /DE/ · CIK 0000797468 · 10% owner

OXY USA INC · CIK 0000728399 · 10% owner

OXY Oil Partners, Inc. · CIK 0001785615 · 10% owner

Baseball Merger Sub 2, Inc. · CIK 0001785593 · 10% owner

ANADARKO PETROLEUM CORP · CIK 0000773910 · 10% owner

ANADARKO HOLDING Co · CIK 0001570992 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnotes

Disclosed balance after: 150,374,176

F1 · kind: On January 16, 2026, Western Gas Resources, Inc. ("WGRI") entered into a Unit Redemption Agreement with the Issuer and the other parties thereto, pursuant to which WGRI transferred and surrendered on February 3, 2026 an aggregate of 15,307,402 common units representing limited partner interests in the Issuer (the "Common Units") to the Issuer in connection with certain amendments to existing operating agreements, as described in the Unit Redemption Agreement.

F1 · price: On January 16, 2026, Western Gas Resources, Inc. ("WGRI") entered into a Unit Redemption Agreement with the Issuer and the other parties thereto, pursuant to which WGRI transferred and surrendered on February 3, 2026 an aggregate of 15,307,402 common units representing limited partner interests in the Issuer (the "Common Units") to the Issuer in connection with certain amendments to existing operating agreements, as described in the Unit Redemption Agreement.

F2 · ownership.nature: Following the transaction reported herein, WGRI holds 140,912,118 Common Units, APC Midstream Holdings, LLC ("APCMH") holds 457,849 Common Units and Anadarko USH1 Corporation ("AUSHI") holds 9,004,209 Common Units. WGRI also is the sole member of Western Midstream Holdings, LLC, the 2% economic general partner of the Issuer.

F3 · ownership.nature: OXY USA Inc. ("OXY USA") is a wholly owned subsidiary of Occidental Petroleum Corporation ("Occidental"). OXY USA owns 100% of the outstanding common stock of OXY Oil Partners, Inc. ("OOP"). OOP owns 100% of the outstanding common stock of Baseball Merger Sub 2, Inc. ("BMS").

F4 · ownership.nature: Anadarko Petroleum Corporation ("APC") is a wholly owned subsidiary of BMS. APC owns (i) 100% of Anadarko Holding Company ("AHC") and (ii) indirectly, 100% of the common stock of WGRI and Kerr-McGee Corporation ("KMG"). WGRI is the sole member of APCMH. KMG and AHC together own 100% of the common stock of Kerr-McGee Worldwide Corporation ("KMWW"), and APC and KMWW together indirectly own 100% of the common stock of AUSH1. Accordingly, OXY USA, OOP, BMS, APC, AHC, WGRI, AUSH1, KMG, APCMH and KMWW are all direct or indirect wholly owned subsidiaries of Occidental.

SEC source: 0001140361-26-003922 · form4.xml · nonDerivative · entry 1

OCCIDENTAL PETROLEUM CORP /DE/ · CIK 0000797468 · 10% owner

WESTERN GAS RESOURCES INC · CIK 0000856716 · 10% owner

APC Midstream Holdings, LLC · CIK 0001601306 · 10% owner

Kerr-McGee Worldwide Corp · CIK 0001699285 · 10% owner

Anadarko USH1 Corp · CIK 0001824936 · 10% owner

KERR MCGEE CORP /DE · CIK 0001141185 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnotes

Disclosed balance after: 150,374,176

F1 · kind: On January 16, 2026, Western Gas Resources, Inc. ("WGRI") entered into a Unit Redemption Agreement with the Issuer and the other parties thereto, pursuant to which WGRI transferred and surrendered on February 3, 2026 an aggregate of 15,307,402 common units representing limited partner interests in the Issuer (the "Common Units") to the Issuer in connection with certain amendments to existing operating agreements, as described in the Unit Redemption Agreement.

F1 · price: On January 16, 2026, Western Gas Resources, Inc. ("WGRI") entered into a Unit Redemption Agreement with the Issuer and the other parties thereto, pursuant to which WGRI transferred and surrendered on February 3, 2026 an aggregate of 15,307,402 common units representing limited partner interests in the Issuer (the "Common Units") to the Issuer in connection with certain amendments to existing operating agreements, as described in the Unit Redemption Agreement.

F2 · ownership.nature: Following the transaction reported herein, WGRI holds 140,912,118 Common Units, APC Midstream Holdings, LLC ("APCMH") holds 457,849 Common Units and Anadarko USH1 Corporation ("AUSHI") holds 9,004,209 Common Units. WGRI also is the sole member of Western Midstream Holdings, LLC, the 2% economic general partner of the Issuer.

F3 · ownership.nature: OXY USA Inc. ("OXY USA") is a wholly owned subsidiary of Occidental Petroleum Corporation ("Occidental"). OXY USA owns 100% of the outstanding common stock of OXY Oil Partners, Inc. ("OOP"). OOP owns 100% of the outstanding common stock of Baseball Merger Sub 2, Inc. ("BMS").

F4 · ownership.nature: Anadarko Petroleum Corporation ("APC") is a wholly owned subsidiary of BMS. APC owns (i) 100% of Anadarko Holding Company ("AHC") and (ii) indirectly, 100% of the common stock of WGRI and Kerr-McGee Corporation ("KMG"). WGRI is the sole member of APCMH. KMG and AHC together own 100% of the common stock of Kerr-McGee Worldwide Corporation ("KMWW"), and APC and KMWW together indirectly own 100% of the common stock of AUSH1. Accordingly, OXY USA, OOP, BMS, APC, AHC, WGRI, AUSH1, KMG, APCMH and KMWW are all direct or indirect wholly owned subsidiaries of Occidental.

SEC source: 0001715126-25-000004 · wk-form4_1761768403.xml · derivative · entry 3

Brown Oscar K · CIK 0001715126 · Director · President & CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 105,318

Underlying: Common Units representing limited partner interests · 52,660 shares

Expires 2027-10-28

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: Each Phantom Unit is the economic equivalent of one WES Common Unit representing limited partnership interests, and upon vesting, will entitle the holder to receive a common unit or, at the discretion of the Board of Directors of the General Partner, cash equal to the Fair Market Value of a Common Unit.

F2 · derivative.exercise_date: These Phantom Units vest ratably over a three-year period on October 28th each year, and will pay distribution equivalent rights in cash on a current basis.

SEC source: 0001715126-25-000004 · wk-form4_1761768403.xml · nonDerivative · entry 2

Brown Oscar K · CIK 0001715126 · Director · President & CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 71,928

SEC source: 0001715126-25-000004 · wk-form4_1761768403.xml · nonDerivative · entry 1

Brown Oscar K · CIK 0001715126 · Director · President & CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 92,650

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0001423902-25-000054 · wk-form4_1747688542.xml · derivative · entry 2

PHILLIPS ROBERT G · CIK 0000901496 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 4,046

Underlying: Common Units representing limited partner interests · 4,046 shares

Expires 2026-02-12

F1 · derivative.exercise_price: Each Phantom Unit is the economic equivalent of one WES Common Unit representing limited partnership interests, and upon vesting, will entitle the holder to receive a common unit or, at the discretion of the Board of Directors of the General Partner, cash equal to the Fair Market Value of a Common Unit.

F1 · price: Each Phantom Unit is the economic equivalent of one WES Common Unit representing limited partnership interests, and upon vesting, will entitle the holder to receive a common unit or, at the discretion of the Board of Directors of the General Partner, cash equal to the Fair Market Value of a Common Unit.