Description of the Study Area

Description of the study area

Description

The Belle Fourche River Watershed is located in the northeast corner of Wyoming and the west-central part of South Dakota. It falls in Mead County and Butte County in South Dakota, and Crook County and Campbell County in Wyoming.The Belle Fourche River Watershed is approximately 2,100,000 acres (3,300 square miles) in size in South Dakota and approximately 2,400,000 acres (3,700 square miles) in Wyoming [Bryce et al., 1998].

The Belle Fourche Watershed rises in northeastern Wyoming, in southern Campbell County approximately 15 miles (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 near Hereford, it turns East North East and joins the Cheyenne approximately 50 miles (80 km) East North East of Rapid City.The point at which the river flows out of Wyoming and into South Dakota is the lowest elevation point in the state of Wyoming at 3,099 feet (945 m). This is the second-highest low point of any US state. The Belle Fourche watershed is approximately 290 miles (470 km) long. The identification number for the Belle Fourche watershed is 1265120. USGS classifies the Belle Fourche river as a stream, and a stream is defined as a linear body of water flowing on the Earth's surface.

Major Streams and Reseviors • Belle Fourche River (main River) • Spearfish Creek • Whitewood Creek • Bear Butte Creek • Horse Creek • Strawberry Creek • Redwater River • Owl Creek

1 Description of the study area

Reseviors BELLE FOURCHE RESERVOIR The Belle Fourche Reservoir is located in Butte County in western South Dakota, about 25 miles east of the Wyoming-South Dakota state line. It is an off-stream storage reservoir supplied by water diverted from the Belle Fourche River. Project construction started during 1905. The first irrigation water was delivered during 1907. Nearly all the water for the Belle Fourche Reservoir is obtained from the Belle Fourche River. Upstream of the diversion dam, the drainage basin area is about 4,000 mi2 . Of this total, about 2,000 mi2 are upstream of the Keyhole Dam and Reservoir in Wyoming.

KEYHOLE RESERVOIR Keyhole Reservoir is owned and operated by the Bureau of Reclamation. Keyhole Reservoir is on the Belle Fourche River about 17 miles northeast of Moorcroft, Wyoming. Keyhole was initially built in the 1950s to provide a supplemental water supply to the Belle Fourche Reservoir and for flood control. The reservoir was completed during 1952. It has a conservation capacity of 193,753 acre-feet. The inflows and storage in the reservoir are 8 allocated 10 percent to Wyoming users and 90 percent to South Dakota users subject to prior rights.

2 Description of the study area