Region
United States
165
Earth (Planet)
82
Antarctica
10
California
8
China
8
Alaska
7
West (U.S.)
7
Asia
6
Colorado
5
Outer space
5
Australia
4
Europe
4
Russia (Federation)
4
Africa, North
3
Appalachian Basin
3
Arizona
3
Brazil
3
Korea (South)
3
Maryland
3
San Francisco Bay Area
3
Andes
2
Arctic Ocean
2
Colombia
2
Germany
2
Greenbelt
2
Hawaii
2
Illinois
2
Illinois Basin
2
Indonesia
2
Italy
2
Latin America
2
Louisiana
2
Mexico
2
Michigan Basin (Mich. and Ont.)
2
New Hampshire
2
New Jersey
2
New Mexico
2
Ohio
2
Pennsylvania
2
Polar regions
2
South Dakota
2
Spain
2
Thailand
2
Tropics
2
Turkey
2
U.S. states
2
Utah
2
Venus (Planet)
2
Vietnam
2
Wisconsin
2
more ...