Region
United States
236
West (U.S.)
25
Texas
10
Southwestern States
9
Galveston Bay
7
North America
6
Southern States
6
Mexico
5
Northeastern States
5
Rocky Mountains
4
Southwest, New
4
Antarctica
3
Arizona
3
Canada
3
New Mexico
3
Soviet Union
3
Utah
3
Africa
2
Arctic regions
2
Colorado
2
East (U.S.)
2
Hawaii
2
Idaho
2
Mexican-American Border Region
2
Mexico, North
2
Middle East
2
Moon
2
Polar regions
2
Russia (Federation)
2
Western Hemisphere
2
Asia, Central
1
Asia, Eastern
1
Atlantic Coast (U.S.)
1
Atlantic Ocean
1
Atlantic States
1
Australia
1
Azerbaijan
1
Bandelier National Monument
1
Bandelier National Monument (N.M.)
1
Blue Mountains (Or. and Wash.)
1
Borah Peak Region
1
British Columbia
1
Caribbean Area
1
Chaco Canyon (N.M.)
1
Challis Region
1
Chimney Rock (Archuleta County, Colo.)
1
Colorado River Watershed (Colo.-Mexico)
1
Developing countries
1
Europe
1
Former Soviet republics
1
more ...