[1] Southwestern operates and maintains 1,380 miles of high-voltage transmission lines, 24 substations, and 46 microwave and VHF radio sites from field offices.

Speaker of the House Sam Rayburn of Texas and Representative Clyde T. Ellis of Arkansas spearheaded the effort to make all federal dams constructed by the U.S. Army Corps of Engineers in the region to stay owned and operated by the military while the hydroelectric power stations were to be managed and marketed by the new Southwestern Power Administration.

In the late 1930s Rayburn and Ellis were able to secure dams in Denison, TX and Norfork, AR in separate independent projects for their House district constituents.

The SWPA (as well as the establishment of the other three Power Marketing Administrations) and the guaranteed cheap electricity from dams helped the REA's goals to be realized.

This was crucial because private utility companies were hoping for the dams to be turned over to the Federal Works Administration during World War II.