BLACK HILLS (PRESIDIO COUNTY)
BLACK HILLS (Presidio County). The Black Hills are located just east of the Atchison, Topeka and Santa Fe Railway in southwestern Presidio County (at 29°37' N, 104°08' W). With elevations of 3,637 and 3,499 feet above sea level, the summits rise an average of 568 feet over Black Hills Creek, which runs along the western edge of the hills. The hills were formed by successive flows of volcanic rhyolite and basalt. They stand in desert mountain terrain cut by numerous rugged canyons. Vegetation in the area consists primarily of sparse grasses, cacti, and desert conifer and oak shrubs.
The following, adapted from the Chicago Manual of Style, 15th edition, is the preferred citation for this article."BLACK HILLS (PRESIDIO COUNTY)," Handbook of Texas Online (http://www.tshaonline.org/handbook/online/articles/rjb39), accessed December 10, 2013. Published by the Texas State Historical Association.