Region
United States
87
Alaska
6
Menominee County (Wis.)
4
Menominee Indian Reservation (Wis.)
4
Sacramento Metropolitan Area (Calif.)
4
South Carolina
4
California
3
National Petroleum Reserve
3
National Petroleum Reserve (Alaska)
3
Hawaii
2
Massachusetts
2
New Mexico
2
West (U.S.)
2
Appalachian Basin
1
Arizona
1
Balkan Peninsula
1
Belly River Region (Mont. and Alta.)
1
Cascade Range
1
Columbia River Watershed
1
Crater Lake
1
Earth (Planet)
1
East Asia
1
Florida
1
Fort Huachuca
1
Great Plains
1
Klamath River Watershed (Or. and Calif.)
1
Livengood Region
1
Long Valley Region (Mono County)
1
Louisiana
1
Massachusetts Bay
1
Massachusetts Bay (Mass.)
1
Maui
1
Mexico, Gulf of
1
Middle Atlantic States
1
Middle West
1
Mimbres Mountains Region
1
Mimbres Mountains Region (N.M.)
1
Minnesota
1
Mirror Lake Watershed (Grafton County)
1
Mississippi River
1
Mojave River Watershed
1
Mono Lake Region
1
Nevada
1
New England
1
New Hampshire
1
New York (State)
1
North Pacific Region
1
Northeastern States
1
Oahu
1
Oregon
1
more ...