Simpson's Spring was one of the important desert stations on the Pony Express and Overland Stage Route between St. Joseph, Missouri and Sacramento, California. From this point, water was carried for west-bound travelers and animals. The spring was discovered by Captain J.M. Simpson, U.S. Army in 1858. The first East-bound Pony Express courier halted here about 5 p.m. April 7, and West-bound about 2 a.m. April 10, 1860. The last riders passed about October 22, 1861. The coming of the overland telegraph made it inadvisable to continue the Pony Express.