Subject
National parks and reserves
Historic sites
32
Land use
10
Grand Teton National Park (Wyo.)
9
Historic buildings
9
Trails
8
Gateway National Recreation Area (N.J. and N.Y.)
6
National monuments
6
Big Cypress National Preserve (Fla.)
5
Recreation areas
5
Wilderness areas
5
Battlefields
4
Cape Lookout National Seashore (N.C.)
4
Delaware Water Gap National Recreation Area (N.J. and Pa.)
4
Glacier National Park (Mont.)
4
Hiking
4
Middle Delaware National Scenic and Recreational River (N.J. and Pa.)
4
Military parks
4
Antietam National Battlefield (Md.)
3
Chamizal National Memorial (El Paso, Tex.)
3
Curecanti National Recreation Area (Colo.)
3
Forest reserves
3
Indiana Dunes National Park (Ind.)
3
Landscape protection
3
New River Gorge National Park and Preserve (W. Va.)
3
Roads
3
Sequoia and Kings Canyon National Parks (Calif.)
3
Voyageurs National Park (Minn.)
3
Apostle Islands National Lakeshore (Wis.)
2
Architecture
2
Automobile travel
2
Badlands National Park (S.D.)
2
Bering Land Bridge National Preserve (Alaska)
2
Bicycle trails
2
Black Canyon of the Gunnison National Park (Colo.)
2
Buildings
2
Camp sites, facilities, etc
2
Cane River Creole National Historical Park (La.)
2
Canyonlands National Park (Utah)
2
Cape Cod National Seashore (Mass.)
2
Colonial National Historical Park (Va.)
2
Colorado
2
Engineering History
2
Environmental impact analysis
2
Everglades National Park (Fla.)
2
Fort Davis National Historic Site (Tex.)
2
Fort McHenry National Monument and Historic Shrine (Baltimore, Md.)
2
Jean Lafitte National Historical Park and Preserve (La.)
2
National parks and reserves Management
2
Nature conservation
2
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