Region
United States
11
Colorado
5
Grand Valley (Colo. and Utah)
5
New Jersey
3
California
2
Iowa
2
Maryland
2
Michigan
2
Pennsylvania
2
Texas
2
Washington (State)
2
Alabama
1
Albany (N.Y.)
1
Australia
1
Cedar Rapids
1
Chesapeake Bay (Md. and Va.)
1
Colorado River (Colo.-Mexico)
1
Colorado River Watershed (Colo.-Mexico)
1
Columbia
1
Contra Costa Canal
1
Denver
1
Des Moines
1
Durham
1
Erie, Lake
1
Fairfax County
1
Florida
1
Grand Valley
1
Great Lakes (North America)
1
Hubbard Creek Lake
1
Hubbard Creek Reservoir
1
Interstate Sanitation District
1
Kentucky
1
Louisiana
1
Melbourne
1
Mesa County
1
Minnesota
1
Monongalia County
1
Montgomery
1
Mount Clemens
1
New Orleans
1
New Providence
1
New York (State)
1
North Carolina
1
Northeastern States
1
Ohiopyle State Park
1
Parachute (Colo.)
1
Phoenixville
1
Rohnert Park
1
Runnels County
1
Seattle Metropolitan Area
1
more ...