Pecan Bayou, one of the five major tributaries of the Colorado River of Texas, is aptly named, for it is a slow-moving stream fed by over twenty creeks. Many area residents believe it is the westernmost bayou in the United States. Pecan Bayou has two main branches. The North Prong headwaters originate on the Callahan Divide in northwestern Callahan County and eastern Taylor County near Eula (at 32°22' N, 99°34' W), twelve miles north of the South Prong's head (at 32°15' N, 99°41' W). The North Prong moves southeast through Callahan County and is dammed six miles south of Clyde to form Lake Clyde. Fed by three small creeks, the two prongs merge in south central Callahan County (at 32°13' N, 99°26' W) and cross the Coleman county line. Four more creeks feed it in Coleman County, and the bayou has fourteen additional small tributaries in Brown and Mills counties. A dam on Pecan Bayou seven miles north of Brownwood forms Lake Brownwood. Below the lake the stream runs just east of the city and enters the Colorado River in Mills County (at 31°25' N, 98°43' W) ninety miles southeast of its headwaters.