Angostura Reservoir is a reservoir on the Cheyenne River in Fall River County, South Dakota, United States. It was created after the construction of Angostura Dam in 1949 for irrigation by the U.S. Bureau of Reclamation. "Angostura" means "narrows" in Spanish. The reservoir covers an area of 4407 acre, has a surface elevation of 3,127 ft, and a maximum depth of 75 ft. The Angostura Recreation Area surrounds the lake and is a popular location for boating, swimming, camping, and fishing. The lake supports populations of walleye, northern pike, smallmouth bass, and sunfish. As one of the only large bodies of water in the area, Angostura Reservoir is also an important location for migratory birds.