Region
United States
22
Tennessee
7
West (U.S.)
7
Arizona
2
Cape Lookout National Seashore (N.C.)
2
North Carolina
2
Portsmouth (N.C.)
2
Asia
1
California
1
Europe
1
Gettysburg National Military Park (Pa.)
1
Greece
1
Maryland, Southern
1
Montezuma Castle National Monument
1
Montezuma Castle National Monument (Ariz.)
1
Moon
1
North America
1
Outer space
1
Petrified Forest National Park
1
Petrified Forest National Park (Ariz.)
1
Rome
1
Southern States
1
Study and teaching (Primary)
1
United States, West
1
Washington Metropolitan Area
1
West United States
1