Belle Fourche River, South Dakota

The Belle Fourche River (pronounced bel FYOOSH) is a tributary of the Cheyenne River, approximately 290 mi (467 km) long, in the U.S. states of Wyoming and South Dakota. Via the Cheyenne and Missouri rivers, it is part of the watershed of the Mississippi River. It rises in northeastern Wyoming, in southern Campbell County, approximately 15 mi. (24 km) north of Wright. It flows northeast, past Moorcroft and Devils Tower. Near the state line with Montana, it turns abruptly southeast and flows in western South Dakota, past Belle Fourche and around the north side of the Black Hills. In southern Meade County near Hereford, it turns ENE and joins the Cheyenne approximately 50 mi (80 km) ENE of Rapid City. The point at which the river flows out of Wyoming and into South Dakota is the lowest point in the State of Wyoming at 945 meters (3,099 feet) elevation. This is the second-highest low point of any U.S. state. The river provides significant flood control, recreation and irrigation for agriculture in western South Dakota. The total irrigation area of the river in South Dakota is approximately 57,000 acres (231 km²).