Region
United States
33
Colorado
7
Europe
6
North America
6
Russia
6
West (U.S.)
5
Moon
4
New Mexico
4
Utah
4
Africa
3
Canada
3
Great Britain
3
Southwest, New
3
Texas
3
Alaska
2
Arizona
2
California
2
China
2
Greenland
2
Israel
2
Jerusalem
2
Louisiana
2
Northwest, Pacific
2
Soviet Union
2
America
1
Antarctica
1
Arctic regions
1
Asia
1
Atlantic Coast (North America)
1
Australia
1
Baltic States
1
Baton Rouge Region
1
Black Hills Region (S.D. and Wyo.)
1
Canada, Northern
1
Castle Valley (Emery County)
1
Central America
1
Delaware River Watershed (N.Y.-Del. and N.J.)
1
Denver Basin
1
Developing countries
1
Earth (Planet)
1
East (U.S.)
1
England
1
Former Soviet republics
1
Garfield County
1
Great Plains
1
Great Salt Lake (Utah)
1
Illinois
1
Illinois River
1
Illinois River (Ill.)
1
Ireland
1
more ...