Black River. 1 River rising in SE Mo. and flowing c.300 mi (480 km) SE, then SW to the White River near Newport, Ark. It is partly navigable. Clearwater Dam is on the river near Piedmont, Mo. 2 River of N N.Y., c.120 mi (190 km) long, rising in the Adirondack Mts. and flowing mainly N and W to Black River Bay, an inlet of Lake Ontario. Its falls provide power for factories and mills. 3 River, c.160 mi (260 km) long, rising in central Wis. and winding SW to the Mississippi River at La Crosse, Wis. It has been used to transport lumber, coal, and petroleum products. Big Manitou Falls, the highest falls in Wisconsin (165 ft/50 m), are in the river.