Thorndale is an incorporated community on U.S. Highway 79 and Farm Road 486, twelve miles west of Rockdale in southwestern Milam County. It was established in 1878 about three miles west of its present site, shortly after the International-Great Northern Railroad was built through the area. A railroad employee named the town after the region\'s abundant thorny vegetation-mesquite thorn, prickly pear, and sagebrush.