Region
Colorado
10
United States
4
Colorado River (Colo.-Mexico)
3
Arizona
2
Colorado River Watershed (Colo.-Mexico)
2
West (U.S.)
2
Arkansas River
1
California
1
China
1
Colorado River Delta (Mexico)
1
Flagstaff
1
Fryingpan River (Colo.)
1
Illinois
1
Mesa County
1
Nile River Watershed
1
North America
1
Phoenix
1
Raft River Watershed (Utah and Idaho)
1
Snake Valley, Nev. and Utah
1
Tucson
1
Utah
1
Wyoming
1
Yellowstone River Valley
1
Yellowstone River Watershed
1