Region
Aberdeen Proving Ground
1
Adams County
1
Alabama
1
Alaska
3
Albuquerque
1
Arizona
1
Arkansas
2
Assateague Island (Md. and Va.)
1
Atlanta
2
Bartlesville
1
Belize
1
Big Cypress Reservation
1
Big Cypress Reservation (Fla.)
1
Boise
1
Brazoria County
2
Bridgeport
1
California
5
Canada
1
Casper
1
Chattanooga
1
Chesapeake Bay (Md. and Va.)
4
Chesapeake Bay Watershed
2
Cincinnati
1
Clackamas County
1
Colorado
2
Colorado Plateau
1
Connecticut
2
Daly West Mine (Utah)
1
Delaware
1
Denver
1
Developing countries
2
East (U.S.)
2
El Paso
1
Escambia County
1
Europe
2
Everglades
1
Flathead Indian Reservation
1
Flathead Lake (Mont.)
1
Florida
10
Fort Peck Indian Reservation
1
Fort Peck Indian Reservation (Mont.)
1
Georgia
2
Goldenrod (Fla.)
1
Gray (Me.)
1
Great Lakes (North America)
6
Great Lakes Region (North America)
1
Great Lakes Watershed (North America)
1
Green Bay
1
Haverford
1
Hialeah
2
more ...