NIOBRARA RIVER

river rising near Lusk, Wyo., U.S., and flowing east across the High Plains, the northern edge of the sandhills, and the low eastern plains of Nebraska to join the Missouri at the village of Niobrara, Neb., at the South Dakota line. The name is of Indian origin and means running, or spreading, water. Both are apt designations because the Niobrara has a more uniform flow than do most plains streams, due to steady groundwater contributions from tributaries in the sandhills, while in its lower course it is wide and shallow. The river is 447 miles (720 km) long and drains 12,000 square miles (31,080 square km). Box Butte Dam (1946) is on the river near Marsland, Neb.