Author/Creator
- Geological Survey (U.S.)531
- United States. National Park Service227
- United States. Forest Service221
- United States. Bureau of Land Management158
- U.S. Fish and Wildlife Service111
- United States. Bureau of the Census107
- United States. Department of Labor. Manpower Administration41
- United States39
- Gap Analysis Program (U.S.)32
- Geometronics Service Center (U.S.)32
- United States. Forest Service. Eastern Region32
- United States. Forest Service. Rocky Mountain Region31
- United States. Environmental Protection Agency29
- United States. Bureau of Land Management. California Desert District26
- United States. Forest Service. Pacific Northwest Region22
- United States. Central Intelligence Agency20
- United States. Forest Service. Southern Region20
- United States. Forest Service. Intermountain Region18
- Office for Official Publications of the European Communities17
- Lovell Johns, ltd16