Known as early as 1840 to settlers and prospectors, Sand Springs was a noted watering place on pioneer trails where travelers camped near strong currents of water boiling up at the foot of a rocky bluff. The sandstone face of the bluff became an inscription rock where travelers carved names or initials and the dates of their visits, sometimes to assure friends or relatives who would follow later over the same trail. Prospectors camped here, including California-bound gold seekers passing this way in 1849-1850s. In 1857, the spot was mapped as a watering place for John Butterfield's southern overland mail coaches racing from Saint Louis to San Francisco. After the Civil War, from 1861-65, many cattle herds stopped here for water while being driven north to market. When the Missouri, Kansas and Texas Railroad was built to Denison townsite in 1872, Sand Springs gained new importance by feeding Waterloo Lake, built in the late 1800s and used for many years before 1908 as the city's main water supply. The old campsites were inundated, and other steps in man's progress reduced the flow of the water, but the area remained a popular picnic ground for years, and its history survives in the weathered carvings still visible on the inscription rocks.