TORNILLO CREEK. Tornillo Creek rises in the Christmas Mountains four miles south of the Corazones Peaks and two miles north of the Big Bend National Park boundary in south central Brewster County (at 29°26' N, 103°25' W) and runs southeast for forty-five miles to its mouth on the Rio Grande, in Big Bend National Park two miles southwest of Boquillas (at 29°11' N, 103°00' W). The creek is intermittent for the first twenty-four and last twelve miles of its length. It is joined by Cottonwood Draw five miles east of the Grapevine Hills. Steep to gentle slopes in the area are surfaced by variable soils that support scrub brush and grasses.
The following, adapted from the Chicago Manual of Style, 15th edition, is the preferred citation for this article."TORNILLO CREEK," Handbook of Texas Online (http://www.tshaonline.org/handbook/online/articles/rbt66), accessed August 29, 2015. Uploaded on June 15, 2010. Published by the Texas State Historical Association.