CALF CREEK (Grayson County). Calf Creek, also known as Shannon Creek, rises just northeast of Sherman in east central Grayson County (at 33°42' N, 96°34' W) and runs southeast for seven miles to its mouth on Choctaw Creek, seven miles east of Sherman (at 33°40' N, 96°29' W). It traverses flat to rolling prairie with a dark calcareous clay and clay loam surface that supports oak, juniper, mesquite, cacti, and grasses.