The Potomac Appalachian Transmission Highline (PATH) is a proposed $1.8 billion 200-plus mile long 765 kV extra high voltage electric transmission line linking the Amos substation (located adjacent to the nearly forty year old 2,933 MW coal-fired John E. Amos Power Plant located in western West Virginia) with a new substation proposed to be built in Frederick County, Maryland. PATH has been recommended by PJM Interconnection, the regional transmission organization. PJM is a consortium of power companies, transmission companies and other interested utilities.

PATH is a joint project of AEP and Allegheny Power. If completed, it would cross West Virginia, pass through Frederick and Loudoun Counties in Virginia before terminating in Maryland. There are several alternatives routes under consideration at this time. PATH will select one or more routes to present to state utility regulators as part of its application for Certificates of Convenience and Necessity in each of the three states. Towers for a 765 kV line are usually a lattice steel structure between 140 and 160 feet tall. New or additional rights of way will be needed for entire length of the proposed line.