SALT FORK. Salt Fork rises on the breaks of the Llano Estacado near the north rim of Palo Duro Canyon in southwestern Armstrong County (at 34°59' N, 101°29' W) and runs south for eight miles to its mouth on the Prairie Dog Town Fork of the Red River (at 34°51' N, 101°25' W). It passes through moderately steep slopes with locally high relief. The soil is made up of shallow silt loams, and the vegetation consists of ranchland grasses and mesquite. Once a part of the JA Ranch holdings, the stream is now near the western boundary of that ranch.