| ONEOK      Partners Intermediate Limited Partnership              | Delaware            |
|-------------------------------------------------------------------|---------------------|
| ONEOK      ILP GP, L.L.C.                                         | Delaware            |
| Bear      Paw Investments, LLC                                    | Delaware            |
| Bear      Paw Energy, LLC                                         | Delaware            |
| Bear      Paw Processing Company (Canada), Ltd.                   | Alberta             |
| Brown      Bear Enterprises, LLC                                  | Delaware            |
| Border      Minnesota Pipeline, LLC                               | Delaware            |
| Black      Mesa Holdings, Inc.                                    | Delaware            |
| Black      Mesa Pipeline, Inc.                                    | Delaware            |
| Black      Mesa Pipeline Operations, L.L.C.                       | Delaware            |
| Black      Mesa Technologies, Inc.                                | Oklahoma            |
| Black      Mesa Technologies Services, LLC (60%)                  | Oklahoma            |
| Border      Midstream Services, Ltd.                              | Alberta             |
| Border      Midwestern Company                                    | Delaware            |
| Midwestern      Gas Marketing Company                             | Delaware            |
| Midwestern      Gas Transmission Company                          | Delaware            |
| Border      Viking Company                                        | Delaware            |
| Viking      Gas Transmission Company                              | Delaware            |
| Crestone      Energy Ventures, L.L.C.                             | Delaware            |
| Crestone      Bighorn, 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            |
| Northern      Border Pipeline Company (general partnership) (50%) | Texas               |
| China      Pipeline Holdings Ltd. (0.81%)                         | Cayman      Islands |
| Guardian      Pipeline, L.L.C.                                    | Delaware            |
| Bighorn      Gas Gathering, L.L.C. (49.0%)                        | Delaware            |
| Fort      Union Gas Gathering, L.L.C. (37.04%)                    | Delaware            |
| Lost      Creek Gathering Company, L.L.C. (35%)                   | Delaware            |
| Chisholm      Pipeline Company (50%)                              | Delaware            |
| Chisholm      Pipeline Holdings, L.L.C.                           | Delaware            |
| Mid      Continent Market Center, L.L.C.                          | Kansas              |
| OkTex      Pipeline Company, L.L.C.                               | Delaware            |
| ONEOK      Arbuckle Pipeline, L.L.C.                              | Delaware            |
| ONEOK      Arbuckle Land Company                                  | Texas               |
| ONEOK      Field Services Company, L.L.C.                         | Oklahoma            |
| ONEOK      Gas Gathering, 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, L.L.C.                                    | Delaware            |

----

| ONEOK      Hydrocarbon, L.P.                                    | Delaware |
|-----------------------------------------------------------------|----------|
| ONEOK      Hydrocarbon GP, L.L.C.                               | Delaware |
| ONEOK      Hydrocarbon Holdings, L.L.C.                         | Delaware |
| ONEOK      Hydrocarbon Southwest, L.L.C.                        | Delaware |
| ONEOK      MB I, L.P.                                           | Delaware |
| ONEOK      Midstream Gas Supply, L.L.C.                         | Oklahoma |
| ONEOK      Mont Belvieu Storage Company, L.L.C.                 | Delaware |
| ONEOK      NGL Pipeline, L.L.C.                                 | Delaware |
| ONEOK      NGL Gathering, L.L.C.                                | Delaware |
| ONEOK      North System, L.L.C.                                 | Delaware |
| ONEOK      Overland Pass Holdings, L.L.C.                       | Oklahoma |
| ONEOK      Pipeline Holdings, L.L.C.                            | Delaware |
| ONEOK      Texas Gas Storage, L.L.C.                            | Texas    |
| ONEOK      Transmission Company, L.L.C.                         | Delaware |
| ONEOK      Underground Storage Company, L.L.C.                  | Kansas   |
| ONEOK      VESCO Holdings, L.L.C.                               | Delaware |
| ONEOK      WesTex Transmission, L.L.C.                          | Delaware |
| Overland      Pass Pipeline Company LLC                         | Delaware |
| Potato      Hills Gas Gathering System (joint venture) (51%)    | Oklahoma |
| Sycamore      Gas System (general partnership) (48.445%)        | Oklahoma |
| Venice      Energy Services Company, L.L.C. (10.1765%)          | Delaware |
| Mont      Belvieu I Fractionation Facility (joint venture)(80%) | Texas    |
| Heartland      Pipeline Company (general partnership) (50%)     | Texas    |