Owners
ATC is a privately owned company. Utilities, municipalities, municipal electric companies and electric cooperatives from Wisconsin, Michigan, Minnesota and Illinois have an ownership stake in ATC.
- Adams-Columbia Electric Cooperative
- Alger Delta Cooperative Electric Association
- City of Algoma
- ALLETE Transmission Holdings, Inc.
- Badger Power Marketing Authority
- Central Wisconsin Electric Cooperative
- Cloverland Electric Cooperative
- City of Columbus
- City of Kaukauna
- Madison Gas & Electric Co.
- Manitowoc Public Utilities
- Marshfield Electric and Water Department
- City of Oconto Falls
- Ontonagon County Rural Electrification Association
- City of Plymouth
- City of Reedsburg
- Rock Energy Cooperative
- City of Sheboygan Falls
- Stoughton Utilities
- City of Sturgeon Bay
- City of Sun Prairie
- Upper Peninsula Public Power Agency
- WEC Energy Group
- Wisconsin Power & Light Co.
- City of Wisconsin Rapids
- WPPI Energy