EXHIBIT 21
SEMGROUP CORPORATION
Subsidiaries
| Entity | Place of Incorporation/Organization | |
| SemGroup Holdings G.P., L.L.C. | Delaware | |
| SemGroup Holdings, L.P. | Delaware | |
| SemOperating G.P., L.L.C. | Oklahoma | |
| SemCap, L.L.C. | Oklahoma | |
| SemGroup Asia, L.L.C. | Delaware | |
| SemManagement, L.L.C. | Delaware | |
| SemStream, L.P. | Delaware | |
| SemGroup Subsidiary Holding, L.L.C. | Delaware | |
| Alpine Holding, LLC | Oklahoma | |
| Rose Rock Midstream Holdings, LLC | Delaware | |
| Rose Rock Midstream Corporation | Delaware | |
| Rose Rock Midstream GP, LLC | Delaware | |
| Rose Rock Midstream, L.P. | Delaware | |
| Rose Rock Midstream Operating, LLC | Delaware | |
| Rose Rock Midstream Energy GP, LLC | Delaware | |
| Rose Rock Finance Corporation | Delaware | |
| Rose Rock Midstream Field Services, LLC | Delaware | |
| Rose Rock Midstream Crude, L.P. | Delaware | |
| SemCrude Pipeline, L.L.C. | Delaware | |
| Wattenberg Holding, LLC | Oklahoma | |
| Eaglwing, L.P. | Oklahoma | |
| SemDevelopment, L.L.C. | Delaware | |
| Rocky Cliffs Pipeline, L.L.C. | Delaware | |
| Glass Mountain Holding, LLC | Oklahoma | |
| SemFuel, L.P. | Texas | |
| SemFuel Transport, LLC | Wisconsin | |
| SemProducts, L.L.C. | Oklahoma | |
| SemGas, L.P. | Oklahoma | |
| SemKan, L.L.C. | Oklahoma | |
| SemGas Gathering, L.L.C. | Oklahoma | |
| SemGas Storage, L.L.C. | Oklahoma | |
| Greyhawk Gas Storage Company, L.L.C. | Delaware | |
| Steuben Development Company, LLC | Delaware | |
| Grayson Pipeline, L.L.C. | Oklahoma | |
| Mid-America Midstream Gas Services, L.L.C. | Oklahoma | |
| SemCanada, L.P. | Oklahoma | |
| SemCanada Crude Company | Nova Scotia | |
| SemCanada II, L.P. | Oklahoma | |
| SemCAMS ULC | Nova Scotia | |
| SemCAMS Redwillow ULC | Nova Scotia | |
| SemGreen, L.P. | Delaware | |
| SemBio, L.L.C. | Delaware | |
| SemMaterials, L.P. | Oklahoma | |
| New Century Transportation LLC | Delaware | |
EXHIBIT 21
| K.C. Asphalt, L.L.C. | Colorado | |
| SemTrucking, L.P. | Oklahoma | |
| SemMaterials Vietnam, L.L.C. | Oklahoma | |
| SemMexico, L.L.C. | Oklahoma | |
| SemMexico Materials HC S. de R.L. de C.V. | Mexico | |
| SemMaterials HC Mexico S. de R.L. de C.V. | Mexico | |
| SemMaterials Mexico S. de R.L. de C.V. | Mexico | |
| SemMaterials SC Mexico S. de R.L. de C.V. | Mexico | |
| SemGroup Europe Holding L.L.C. | Delaware | |
| SemEuro Limited | United Kingdom | |
| SemLogistics Milford Haven Limited | United Kingdom | |
| SemGroup Netherland B.V. | The Netherlands | |