Region
United States
84
California
10
Texas
9
Colorado
7
China
4
Middle East
4
Pennsylvania
4
Alaska
3
Argentina
3
Developing countries
3
Montana
3
Denver
2
Europe
2
European Union countries
2
Florida
2
Great Britain
2
Illinois
2
India
2
Italy
2
Japan
2
New York
2
New York (State)
2
North America
2
Ohio
2
Peru
2
Philadelphia
2
Soviet Union
2
Afghanistan
1
Africa
1
Africa, English-speaking
1
Africa, North
1
Arizona
1
Asia
1
Austin
1
Australia
1
Baltimore
1
Bangladesh
1
Battle Mountain Mining District
1
Big Cypress Reservation
1
Big Cypress Reservation (Fla.)
1
Channel Islands
1
Channel Islands National Park
1
Channel Islands National Park (Calif.)
1
Char Jabbar
1
Chechni⁻Ła (Russia)
1
Chicago
1
Chicago Metropolitan Area
1
Cleveland
1
Cyprus
1
Dab̜rowa Basin (Poland and Czech Republic)
1
more ...