EX-21 6 oke10-k2020exhibit21.htm SUBSIDIARIES
Exhibit 21
ONEOK, Inc.
SUBSIDIARIES OF THE COMPANY
AS OF DECEMBER 31, 2020

Subsidiaries | State of Incorporation or Organization
Bighorn Gas Gathering, L.L.C. (49.0%) | Delaware
Black Mesa Holdings, Inc. | Delaware
Black Mesa Pipeline, Inc. | Delaware
Black Mesa Pipeline Operations, L.L.C. | Delaware
Black Mesa Technologies, Inc. | Oklahoma
Border Midwestern Company | Delaware
Chisholm Pipeline Company (50%) | Delaware
Chisholm Pipeline Holdings, L.L.C. | Delaware
Crestone Energy Ventures, L.L.C. | Delaware
Crestone Gathering Services, L.L.C. | Delaware
Crestone Powder River, L.L.C. | Delaware
Crestone Wind River, L.L.C. | Delaware
Fort Union Gas Gathering, L.L.C. (57.405%) | Delaware
Guardian Pipeline, L.L.C. | Delaware
Heartland Pipeline Company (general partnership) (50%) | Texas
Lost Creek Gathering Company, L.L.C. (35%) | Delaware
Mid Continent Market Center, L.L.C. | Kansas
Midwestern Gas Transmission Company | Delaware
Mont Belvieu I Fractionation Facility (joint venture) (80%) | Texas
Northern Border Pipeline Company (general partnership) (50%) | Texas
OkTex Pipeline Company, L.L.C. | Delaware
ONEOK Arbuckle II Pipeline, L.L.C. | Oklahoma
ONEOK Arbuckle North Pipeline, L.L.C. | Delaware
ONEOK Arbuckle Pipeline, L.L.C. | Delaware
ONEOK Bakken Pipeline, L.L.C. | Delaware
ONEOK Bushton Processing, L.L.C. | Delaware
ONEOK Elk Creek Pipeline, L.L.C. | Oklahoma
ONEOK Energy Services Company, II | Delaware
ONEOK Energy Services Company, L.P. | Texas
ONEOK Energy Services Holdings, L.L.C. | Oklahoma
ONEOK Field Services Company, L.L.C. | Oklahoma
ONEOK Gas Storage Holdings, L.L.C. | Delaware
ONEOK Gas Storage, L.L.C. | Oklahoma
ONEOK Gas Transportation, L.L.C. | Oklahoma
ONEOK Hydrocarbon GP, L.L.C. | Delaware
ONEOK Hydrocarbon Holdings, L.L.C. | Delaware
ONEOK Hydrocarbon Southwest, L.L.C. | Delaware
ONEOK Hydrocarbon, L.L.C. | Delaware
ONEOK Hydrocarbon, L.P. | Delaware
ONEOK ILP GP, L.L.C. | Delaware
ONEOK Leasing Company | Delaware

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ONEOK MB I, L.P. | Delaware
ONEOK Midstream Gas Supply, L.L.C. | Oklahoma
ONEOK Mont Belvieu Properties, L.L.C. | Delaware
ONEOK Mont Belvieu Storage Company, L.L.C. | Delaware
ONEOK NGL Gathering, L.L.C. | Delaware
ONEOK NGL Pipeline, L.L.C. | Delaware
ONEOK North System, L.L.C. | Delaware
ONEOK Northern Border Pipeline Company Holdings, L.L.C. | Oklahoma
ONEOK Overland Pass Holdings, L.L.C. | Oklahoma
ONEOK Parking Company, L.L.C. | Delaware
ONEOK Partners GP, L.L.C. | Delaware
ONEOK Partners Intermediate Limited Partnership | Delaware
ONEOK Partners, L.P. | Delaware
ONEOK Permian NGL Operating Company, L.L.C. | Delaware
ONEOK Pipeline Holdings, L.L.C. | Delaware
ONEOK Rockies Investments, L.L.C. | Delaware
ONEOK Rockies Midstream, L.L.C. | Delaware
ONEOK Services Company, L.L.C. | Oklahoma
ONEOK Southeast Texas NGL Pipeline, L.L.C. | Oklahoma
ONEOK Sterling III Pipeline, L.L.C. | Oklahoma
ONEOK Texas Gas Storage, L.L.C. | Texas
ONEOK Underground Storage Company, L.L.C. | Kansas
ONEOK Unit Holdings, Inc. | Delaware
ONEOK VESCO Holdings, L.L.C. | Delaware
ONEOK West Texas NGL Pipeline, L.L.C. | Texas
ONEOK Western Trail Pipeline, L.L.C. | Oklahoma
ONEOK WesTex Transmission, L.L.C. | Delaware
Overland Pass Pipeline Company LLC (50%) | Delaware
Roadrunner Gas Transmission Holdings, LLC (50%) | Delaware
Roadrunner Gas Transmission, LLC (100% owned by Roadrunner Gas Transmission Holdings, LLC) | Delaware
Venice Energy Services Company, L.L.C. (10.1765%) | Delaware
Viking Gas Transmission Company | Delaware

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