Region
United States
980
China
8
California
5
Washington (D.C.)
5
Canada
4
Israel
4
North America
4
Arizona
3
Colorado
3
Egypt
3
Europe
3
Gulf States
3
Russia (Federation)
3
Washington (State)
3
West Virginia
3
Colorado River (Colo.-Mexico)
2
Colorado River Valley (Colo.-Mexico)
2
European Economic Community countries
2
Florida
2
France
2
Gateway National Recreation Area (N.J. and N.Y.)
2
Greece
2
Indiana
2
Iran
2
Iraq
2
Las Vegas
2
Maryland
2
Mexico
2
Michigan
2
Middle East
2
Minnesota
2
Nevada
2
Raleigh County
2
Utah
2
Virginia
2
Acadia National Park (Me.)
1
Africa
1
Alabama
1
Arab countries
1
Arkansas River
1
Australia
1
Balkan Peninsula
1
Capitol Reef National Park (Utah)
1
Chelsea
1
Cibola National Wildlife Refuge
1
Connecticut
1
Cook County
1
Cyprus
1
Delaware
1
Denver
1
more ...