SAND CREEK (Grayson County). Sand Creek rises three miles northwest of Sherman in central Grayson County (at 33°41' N, 96°41' W), skirts the southwestern section of Sherman, and runs southeast for seven miles to its mouth on Postoak Creek, just west of Sherman (at 33°37' N, 96°37' W). Flat to rolling prairie of the area is surfaced by dark, commonly calcareous clays and clay and sandy loams that support water-tolerant hardwood, mesquite, conifers, and various grasses. The region has served as range and crop land, although urban development was present in the late 1900s.