The Salt Fork of the Brazos River rises at an elevation of about 3,000 feet two miles southwest of Caprock in south central Crosby County (at 33°29' N, 101°25' W). The upper stretches of the river are intermittent. On its eastward-tending journey of 175 miles the Salt Fork travels through thinly settled country and passes through no communities. Numerous oilfields are located along the river's path. The Salt Fork runs through south central Crosby, northeast Garza, central Kent, and northern Stonewall counties before joining the Brazos River two miles west of the Stonewall-Haskell county line and about twelve miles northeast of Old Glory (at 33°16' N, 100°01' W). The river descends some 1,500 feet from its headwaters to its mouth, passing through flat to moderately steep terrain. Along its course clay, silt, and sandy loams support mesquite, grasses, and conifers.