Topography: The Colorado River runs from northwest to southeast and flows through Glen Flora and Wharton. The county is drained by Mustang Creek in the extreme west, the Colorado River in the central portions, and the San Bernard River and West Bernard Creek in the eastern portions. Level to undulating plains rise toward the north and are marked by a timber belt of ash, pecan, live oak and other varieties of hardwood trees along the Colorado River. In an area referred to as Bay Prairie, prairie and bunch grasses, mesquite, and oak predominate. The upper northeastern portion, Lissie Prairie, is treeless with prairie and bunch grasses. Altitude varies from 50 to 200 feet.