The Common Use System (CUS) is a joint transmission system Basin Electric Power Cooperative participates in with Black Hills Power and Powder River Energy Corporation (PRECorp).

The Common Use System has filed with the FERC a joint open-access transmission tariff that provides transmission service over these utilities' combined 230-kilovolt (kV) and limited 69-kV transmission facilities within areas of Southwestern South Dakota and Northeastern Wyoming. As of December 2012, the system is made up of 910 circuit miles of which 279 miles are owned by Basin Electric.

The joint open-access transmission tariff also provides for the transmission service associated with the 200-MW Direct Current (DC) tie facility located at Rapid City, SD. This facility is jointly owned by Black Hills Power and Basin Electric.

Black Hills Power serves as tariff administrator and provides the OASIS management for the tariff. The Common Use System OASIS information is located at www.oatioasis.com/bhbe.