Region
Afghanistan
2
Africa, North
1
Alabama
3
Alaska
10
Algeria
1
America
5
American Samoa
3
Antarctica
1
Arab countries
2
Arctic National Wildlife Refuge
2
Argentina
2
Arizona
17
Arkansas
2
Arlington
3
Asia
5
Atlanta
1
Atlantic Coast
1
Atlantic Coast (U.S.)
2
Australia
7
Baltimore
2
Belle Fourche River (Wyo. and S.D.)
1
Boerne (Tex.)
1
Border States (U.S. Civil War)
1
Boston
2
Boston (Mass.)
1
Botswana
1
Brazil
2
British Columbia
1
California
21
California, Southern
1
Cambodia
1
Canada
52
Canandaigua
2
Care Fear River
1
Caribbean Area
1
Central America
25
Chaco Canyon
2
Chaco Culture National Historical Park
2
Chaco Culture National Historical Park (N.M.)
2
Charleston
1
Cherokee Nation
1
Chester County
1
Cheyenne River Indian Reservation (S.D.)
1
Cheyenne River Sioux Tribe of the Cheyenne River Reservation, South Dakota
1
Chicago
2
Chile
2
China
20
Christiansted National Historic Site (United States Virgin Islands)
2
Coeur d'Alene Mining District
1
Coeur d'Alene Mining District (Idaho)
1
more ...