CALLAHAN DIVIDE. The Callahan Divide, named for Callahan County, is a range of hills that extend twenty-six miles from west to southeast through Taylor and Callahan counties and that separate the Brazos River from the Colorado River (the center point of the range is 32°18' N, 99°51' W). The divide begins near the emergence of Cedar Creek, three miles east of Mountain Pass in central Taylor County, proceeds through Buffalo Gap, and concludes near Lytle Gap at the intersection of Farm roads 1178 and 36, a mile north of Dudley in west central Callahan County. Elevations in the range vary from a low of 1,898 feet above sea level at Buffalo Gap to 2,411 at the western end of the Callahan Divide, two miles south of Round Top Mountain.