NM21-765-097 Van Hook Arm of Lake Sakakawea, North Dakota, U.S.A. Winter 1995-1996 The Van Hook Arm of Lake Sakakawea, within the Fort Berthold Indian Reservation, is featured in this spectacular, west-southwest-looking, low-oblique photograph. The Missouri River waters impounded by Garrison Dam, completed in 1956, (not in photograph) formed Lake Sakakawea [200 miles (322 kilometers) long] in western North Dakota. As part of the Missouri River Basin project, Lake Sakakawea and Garrison Dam provide hydroelectric power, flood control, and irrigation for agriculture. The lake has approximately 1600 miles (2576 kilometers) of shoreline for boating, camping, and other recreational activities. Sediment is visible in the lake, and scattered agricultural field patterns extend outward from its shores.