Comal Springs are the largest springs in Texas and the Southwest, with a maximum recorded discharge of 550 cubic feet per second, or 355,608,000 gallons per day, on April 20, 1977. They are a natural discharge of the Edwards (Balcones Fault Zone) aquifer. Water enters this limestone formation through a 1505 square mile recharge zone where the formation meets the ground surface in Kinney, Uvalde, Medina, Bexar, Comal, and Hays counties. Water moves from west to east in the underground formation and serves over one million persons in ranching, irrigation, municipal, and recreational uses. The springs were visited in 1764 by French explorer St. Denis and later became a stop on El Camino Real. In 1845, the area was settled by German immigrants under Prince Carl Solms-Braunfels and called Las Fontanas. Thirteen hundred surrounding acres were purchased for $1,111.