Region
Adirondack Mountains (N.Y.)
1
Afghanistan
1
Africa
24
Africa South of the Sahara
8
Africa, East
2
Africa, French-speaking Equatorial
1
Africa, French-speaking West
1
Africa, North
8
Africa, Southern
2
Africa, Sub-Saharan
4
Alabama
6
Alaska
13
Albuquerque
3
Algeria
1
America
3
American Samoa
4
Antarctic Regions
8
Appalachian Region
1
Arab countries
3
Argonne
1
Arizona
10
Arkansas
3
Armenia
1
Art
1
Asia
41
Asia, Eastern
1
Asia, Southeastern
1
Atlanta
1
Atlanta (Ga.)
1
Audubon National Wildlife Refuge (N.D.)
1
Austin
1
Australasia
3
Australia
36
Balkan Peninsula
1
Bandelier National Monument
1
Bandelier National Monument (N.M.)
1
Baton Rouge
1
Belfast
1
Belgium
1
Bethesda
4
Bethlehem
1
Black Mountain
1
Bogotá (Colombia)
1
Bosnia
1
Bosnia and Hercegovina
1
Bosnia and Herzegovina
2
Boston
1
Boulder
2
Brandywine Creek (Pa. and Del.)
1
Brazil
5
more ...