ALLIGATOR CREEK (Williamson County). Alligator Creek rises three miles east of Bartlett in northeastern Williamson County (at 30°46' N, 97°07' W) and runs southeast for 21½ miles, through Bell and Milam counties, to its mouth on the San Gabriel River, five miles east of San Gabriel in Milam County (at 30°42' N, 97°07' W). Alligators lived in the region in the nineteenth century. The creek flows through flat or gently rolling terrain characterized by clayey soils used predominantly for agriculture.