The Caprock is a range of flat-topped ridges and cliffs stretching from the Texas Panhandle to 20 miles south of this point and extending into New Mexico, and the name also refers to the tough limestone that caps the ridges. Rising sharply 200 to 1,000 feet above the plains, this section, Concho Bluffs, marks the western edge of the Caprock escarpment. Called the "Break of the Plains," it divides the Staked Plains from the North Central Plains of Texas. Observed by Coronado's expedition in 1540-1541, it provided shelter in storms but delayed the entrance of settlers to the Staked Plains. Herds of stampeding cattle at times plunged over its edge. In this area, the Caprock blocked eastbound wagons, including some from the California gold fields in the 1850s. Because of scarce surface water, the Staked Plains were too dry for farming or ranching until wells were drilled and windmills installed. The ridges and canyons here also hindered railroad building. In 1881, workmen earned $2.50 a day, the highest wages ever paid until then on a Texas railroad job, at "Colt's Big Rock Cut," the mile-wide, 17-foot chasm visible here. A tragic accident with dynamite injured several of Colt's men and killed three, and their graves, known to pioneers around Odessa, were on a hill northeast of the tracks but cannot now be found.