Region
West (U.S.)
59
Colorado River Watershed (Colo.-Mexico)
5
Colorado
4
Colorado River (Colo.-Mexico)
3
California
1
Colorado River Region (Colo.-Mexico)
1
Colorado River Valley (Colo.-Mexico)
1
Colorado River Watershed (Colo.-Mex.)
1
Great Basin
1
Hoover Dam (Ariz. and Nev.)
1
Madison Aquifer
1
Nevada
1
New Mexico
1
United States
1