| | | | | | | | | | | | | | |
| Subsidiary * | | State of Incorporation or Organization | | Percent Ownership |
| ATC Holding LLC | | Wisconsin | | 100% |
| American Transmission Company LLC | | Wisconsin | | 60.34% |
| ATC Development Manager, Inc. | | Delaware | | 74.73% |
| ATC Holdco LLC | | Delaware | | 75.17% |
| ATC Management Inc. | | Wisconsin | | 60.32% |
| Bluewater Natural Gas Holding, LLC | | Delaware | | 100% |
| BGS Kimball Gas Storage, LLC | | Delaware | | 100% |
| Bluewater Gas Storage, LLC | | Delaware | | 100% |
| Integrys Holding, Inc. | | Wisconsin | | 100% |
| Michigan Gas Utilities Corporation | | Delaware | | 100% |
| Minnesota Energy Resources Corporation | | Delaware | | 100% |
| Peoples Energy, LLC | | Delaware | | 100% |
| North Shore Gas Company | | Illinois | | 100% |
| Peoples Energy Ventures, LLC | | Delaware | | 100% |
| The Peoples Gas Light and Coke Company | | Illinois | | 100% |
| Wisconsin Public Service Corporation | | Wisconsin | | 100% |
| Wisconsin River Power Company | | Wisconsin | | 50% |
| Wisconsin Valley Improvement Company | | Wisconsin | | 27% |
| WPS Power Development, LLC | | Wisconsin | | 100% |
| WPS Visions, Inc. | | Wisconsin | | 100% |
| Upper Michigan Energy Resources Corporation | | Michigan | | 100% |
| W.E. Power, LLC | | Wisconsin | | 100% |
| Elm Road Generating Station Supercritical, LLC | | Wisconsin | | 100% |
| Elm Road Services, LLC | | Wisconsin | | 100% |
| Port Washington Generating Station, LLC | | Wisconsin | | 100% |
| WEC Business Services LLC | | Delaware | | 100% |
| WEC Infrastructure LLC | | Delaware | | 100% |
| Samson OpCo Holdings LLC | | Delaware | | 80% |
| Sapphire Sky Wind Energy Holdings LLC | | Delaware | | 90% |
| Thunderhead Wind Energy Holdings LLC | | Delaware | | 90% |
| WEC Infrastructure Wind Holding I LLC | | Delaware | | 100% |
| Bishop Hill Energy III Holdings LLC | | Delaware | | 90% |
| Blooming Grove Wind Energy Center Holdings LLC | | Delaware | | 90% |
| Coyote Ridge Wind, LLC | | Oregon | | 80% |
| Upstream Wind Energy Holdings LLC | | Delaware | | 90% |
| WEC Infrastructure Wind Holding II LLC | | Delaware | | 100% |
| Jayhawk Wind, LLC | | Delaware | | 90% |
| Tatanka Ridge Wind, LLC | | Delaware | | 85% |
| WEC Investments, LLC | | Delaware | | 100% |
| Wisconsin Energy Services, LLC | | Wisconsin | | 100% |
| Wisconsin Electric Power Company | | Wisconsin | | 100% |
| Wisconsin Energy Capital Corporation | | Wisconsin | | 100% |
| Wisconsin Gas LLC | | Wisconsin | | 100% |
| Wispark LLC | | Wisconsin | | 100% |
| Wisvest LLC | | Wisconsin | | 100% |