The Agency's Members are located in the control areas of the Agency, Xcel Energy, GRE and Alliant. The Members are connected to the electric transmission systems of the Agency, Xcel Energy, Dairyland, Alliant and GRE. The Agency has constructed various 161 kV transmission lines and other transmission lines and associated substation facilities to more reliably serve its Members.

SMMPA has shared transmission agreements with neighboring utilities for some of its Members and takes Midcontinent Independent System Operator (MISO) network service for some of its other Members.

In 2006, the Agency joined CapX 2020, a joint initiative of transmission-owning utilities in Minnesota and the surrounding region formed to expand the electric high voltage transmission grid to ensure electric reliability for years to come.