**Exhibit      21.1**

|  Name                of Subsidiary            | Jurisdiction                of Incorporationor                Organization | Assumed                Names Under WhichSubsidiary                Does Business                                                  |
|----------------------------------------------------|----------------------------------------------------------------------------|----------------------------------------------------------------------------------------------------------------------------------|
| ATLAS                ENERGY OPERATING COMPANY, LLC | Delaware                                                                   | None                                                                                                                             |
| ATLAS                ENERGY FINANCE CORP.          | Delaware                                                                   | None                                                                                                                             |
| AER                PIPELINE CONSTRUCTION, INC.     | Delaware                                                                   | None                                                                                                                             |
| AIC,                LLC                            | Delaware                                                                   |  None                                                                                                                       |
| ANTHEM                SECURITIES, INC.             | Pennsylvania                                                               | None                                                                                                                             |
| ATLAS                AMERICA, LLC                  | Pennsylvania                                                               |  Atlas                Energy Resources, LLC (in Ohio)Atlas                Energy Resources (in West Virginia and Tennessee) |
| ATLAS                ENERGY MICHIGAN, LLC          | Delaware                                                                   |  Atlas                Energy Resources (in Michigan)                                                                        |
| ATLAS                ENERGY OHIO, LLC              | Ohio                                                                       |  None                                                                                                                       |
| ATLAS                GAS & OIL COMPANY, LLC    | Michigan                                                                   |  None                                                                                                                       |
| ATLAS                NOBLE, LLC                    | Delaware                                                                   |  None                                                                                                                       |
| ATLAS                RESOURCES, LLC                | Pennsylvania                                                               |  Atlas                Energy Resources (in West Virginia and Tennessee)                                                     |
| REI-NY,                LLC                         | Delaware                                                                   |  None                                                                                                                       |
| RESOURCE                ENERGY, LLC                | Delaware                                                                   |  Atlas                Energy Resources (in New York)                                                                        |
| RESOURCE                WELL SERVICES, LLC         | Delaware                                                                   |  None                                                                                                                       |
| VIKING                RESOURCES, LLC               | Pennsylvania                                                               |  None                                                                                                                       |
| WESTSIDE                PIPELINE COMPANY, LLC      | Michigan                                                                   |  None                                                                                                                       |

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