• 5 Map Library (Robinson)

• 4 Biotic communities
• 1 Ecological regions

• 5 Geological Survey (U.S.)
• 4 National Health and Environmental Effects Research Laboratory (U.S.). Western Ecology Division
• 3 United States. Environmental Protection Agency. Office of Research and Development
• 2 United States. Environmental Protection Agency. Region VI
• 1 Corvallis Environmental Research Laboratory
• 1 University of Arkansas, Fayetteville. Center for Advanced Spatial Technologies

• 5 English

• 1 Arkansas
• 1 Indiana
• 1 Kentucky
• 1 Montana
• 1 Ohio
• 1 Oklahoma

Limit year range