The Missouri National Recreational River is a National Recreational River located on the border between Nebraska and South Dakota. The designation was first applied in 1978 to a 59-mile section of the Missouri River between Gavins Point Dam and Ponca State Park. In 1991, an additional 39-mile section between Fort Randall Dam and Niobrara, …The Missouri National Recreational River is a National Recreational River located on the border between Nebraska and South Dakota. The designation was first applied in 1978 to a 59-mile section of the Missouri River between Gavins Point Dam and Ponca State Park. In 1991, an additional 39-mile section between Fort Randall Dam and Niobrara, Nebraska, was added to the designation. These two stretches of the Missouri River are the only parts of the river between Montana and the mouth of the Missouri that remain undammed or unchannelized. The last 20 miles of the Niobrara River and 6 miles of Verdigre Creek were also added in 1991.