DEAVER CREEK. Deaver Creek rises six miles northwest of Dorchester in central Grayson County (at 33°37' N, 96°42' W) and runs northwest for thirteen miles to its mouth on Big Mineral Creek, with which it forms a finger of Lake Texoma six miles northwest of Southmayd (at 33°42' N, 96°47' W). The stream, which is intermittent in its upper reaches, traverses flat to rolling prairie surfaced by dark, commonly calcareous clays that support mesquite, cacti, and various grasses. The area has served as crop and range land.