World War I transfers of land that later became WPAFB include (including the Huffman Prairie Flying Field) along the Mad River leased to the Army by the Miami Conservancy District, the adjacent purchased by the Army from the District for the Fairfield Aviation General Supply Depot, and a complex for McCook Field just north of downtown Dayton between Keowee Street and the Great Miami River. In 1918, Wilbur Wright Field agreed to let McCook Field use hangar and shop space as well as its enlisted mechanics to assemble and maintain airplanes and engines under the direction of Chief of Air Service Mason Patrick.