56     1002 Missouri Headwaters
56     1007 Upper Yellowstone
56     1008 The Big Horn River Basin
56     1009 The Powder and Tongue River Basins
56     1011 Missouri-Little Missouri
56     1012 The Cheyenne River Basin
56     1015 The Niobrara River Basin
56     1018 The North Platte River Basin
56     1019 The South Platte River Basin
56     1404 Great Divide-Upper Green
56     1405 The White and Yampa River Basins
56     1601 The Bear River Basin
56     1602 The Great Salt Lake Basin
56     1704 The Snake River Basin