Subject
Roads
Motor vehicles Recreational use
148
Automobile driving
73
Trails
48
Automobiles Recreational use
29
Off-road vehicle trails
26
Shenandoah National Park (Va.)
24
Indian reservations
20
Indians of North America
20
Automobile driving Recreational use
18
Forest roads
18
Mark Twain National Forest (Mo.)
18
Express highways
17
Outdoor recreation
16
Pike National Forest (Colo.)
14
Bridges
13
Geology
13
Gila National Forest (N.M.)
9
San Isabel National Forest (Colo.)
9
Recreation areas
8
Willamette National Forest (Or.)
8
Los Padres National Forest (Calif.)
7
Roads Design and construction Environmental aspects
7
San Juan National Forest (Colo.)
7
Transportation, Automotive
7
Dixie National Forest (Utah)
6
Environmental impact analysis
6
Federal aid to transportation
6
Klamath National Forest (Calif. and Or.)
6
Monongahela National Forest (W. Va.)
6
Mount Hood National Forest (Or.)
6
Nantahala National Forest (N.C.)
6
Ozark National Forest (Ark.)
6
Pisgah National Forest (N.C.)
6
Rio Grande National Forest (Colo.)
6
Routt National Forest (Colo.)
6
Wilderness areas
6
Automobile travel
5
Camping
5
Flathead National Forest (Mont.)
5
Kisatchie National Forest (La.)
5
Manti-La Sal National Forest (Utah and Colo.)
5
National parks and reserves
5
Paiute Indians
5
Sawtooth National Forest (Idaho and Utah)
5
Shoshoni Indians
5
Transportation
5
Arapaho National Forest (Colo.)
4
Chesapeake and Ohio Canal (Md. and Washington, D.C.)
4
Gunnison National Forest (Colo.)
4
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