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| Subsidiary | | Registered Security | | Guarantor Status |
| Summit Midstream Holdings, LLC | | Senior Notes | | Co-Issuer, Not a guarantor |
| Summit Midstream Finance Corp. | | Senior Notes | | Co-Issuer, Not a guarantor |
| Summit Midstream Partners, LP | | Senior Notes | | Joint and Several, Fully and Unconditionally |
| Grand River Gathering, LLC | | Senior Notes | | Joint and Several, Fully and Unconditionally |
| Red Rock Gathering Company, LLC | | Senior Notes | | Joint and Several, Fully and Unconditionally |
| Summit Midstream Niobrara, LLC | | Senior Notes | | Joint and Several, Fully and Unconditionally |
| DFW Midstream Services LLC | | Senior Notes | | Joint and Several, Fully and Unconditionally |
| Polar Midstream, LLC | | Senior Notes | | Joint and Several, Fully and Unconditionally |
| Epping Transmission Company, LLC | | Senior Notes | | Joint and Several, Fully and Unconditionally |
| Summit Midstream Marketing, LLC | | Senior Notes | | Joint and Several, Fully and Unconditionally |
| Summit Midstream Permian II, LLC | | Senior Notes | | Joint and Several, Fully and Unconditionally |
| Summit Midstream OpCo, LP | | Senior Notes | | Joint and Several, Fully and Unconditionally |
| Meadowlark Midstream Company, LLC | | Senior Notes | | Joint and Several, Fully and Unconditionally |
| Summit DJ-O, LLC | | Senior Notes | | Joint and Several, Fully and Unconditionally |
| Summit DJ-S, LLC | | Senior Notes | | Joint and Several, Fully and Unconditionally |
| Summit DJ-O Operating, LLC | | Senior Notes | | Joint and Several, Fully and Unconditionally |
| Grasslands Energy Marketing LLC | | Senior Notes | | Joint and Several, Fully and Unconditionally |