Region
United States
Japan
3
Outer space
3
California
1
Captain John Smith Chesapeake National Historic Trail
1
Channel Islands National Park (Calif.)
1
Developing countries
1
Fernald
1
Florida
1
Hells Canyon National Recreation Area (Or. and Idaho)
1
Illinois Waterway (Ill.)
1
India
1
Iraq
1
Malheur National Forest
1
Mars (Planet)
1
Middle East
1
Mississippi River
1
Nevada
1
New Mexico
1
North America
1
North Carolina
1
Ohio
1
Oregon
1
Salisbury
1
Texas
1
Virginia
1
Washington (D.C.)
1
Yucca Mountain
1