Hydrology of the Rosebud Indian Reservation, South Dakota

An investigation of the geology and ground-water resources of the Rosebud Indian Reservation, South Dakota, was made at the request of the Bureau of Indian Affairs as part of the U.S. Department of Interior's program for the development of the Missouri River basin.  Originally, the Reservation included all of Mellette, Todd, and Tripp Counties; most of Gregory County, and a small part of Lyman County.  (See index map.)  However, of the 1,500 square miles of land now owned by individual Indians or by the Rosebud Sioux Tribe, nearly 95 percent is located in Mellette and Todd Counties.  Accordingly, the area of this investigation (about 2,700 square miles) was restricted to these two counties.