Regional transmission organization (North America)
A regional transmission organization (RTO) in the United States is an electric power transmission system operator (TSO) that coordinates, controls, and monitors a multi-state electric grid. The transfer of electricity between states is considered interstate commerce, and electric grids spanning multiple states are therefore regulated by the Federal Energy Regulatory Commission (FERC).
Source: Wikipedia — Regional transmission organization (North America) (CC BY-SA 4.0)