Region
Aberdeen Proving Ground
6
Aberdeen Proving Ground (Md.)
2
Ada Aquifer (Okla.)
1
Africa
1
Albany
1
Arapahoe County
5
Arizona
3
Arkansas
1
Asia
1
Beale Air Force Base
1
Beale Air Force Base (Calif.)
1
Bexar County
2
California
3
Caribbean Area
1
Cherryvale
1
Chicago
1
China
2
Clark County
2
Clark County (Wash.)
2
Clark Fork Watershed (Mont. and Idaho)
1
Coconino County
1
Colorado
13
Columbus
1
Denver
2
Douglas County
2
Elbert County
5
Fayetteville
1
Fayetteville (Ark.)
1
Flint
1
Florida
3
Fort Bragg
4
Fort Gordon
2
Fort Gordon (Ga.)
11
Fort Worth
1
Fremont County
1
Gas Works Park (Seattle, Wash.)
1
Georgia
13
Great Britain
1
Great Lakes (North America)
2
Hartwell Lake (S.C. and Ga.)
1
Hualapai Indian Reservation
1
Idaho
3
Illinois
1
Jefferson County
1
Kansas
2
Kansas City
2
Kentucky
3
King County
1
King County (Wash.)
1
Knoxville
1
more ...