Region
Potomac River Watershed
3
Illinois
2
Maryland
2
United States
2
Washington (State)
2
Yakima River Watershed
2
Coeur d'Alene Lake
1
Ellyn, Lake
1
Idaho
1
Magothy Aquifer
1
Missouri
1
Okefenokee Swamp (Ga. and Fla.)
1
Patuxent River Watershed
1
Scofield Reservoir
1
Sheffield Region
1
South Carolina
1
Utah
1