Spatial Coverage
- Coronado National Forest (Ariz. and N.M.)2
- Coronado National Forest.2
- Denver Basin2
- Erie Canal (N.Y.)2
- Erie Canal.2
- Europe2
- George Washington National Forest (Va. and W. Va.)2
- George Washington National Forest.2
- Grand Teton National Park (Wyo.)2
- Grand Teton National Park.2
- Great Basin2
- Great Basin.2
- Great Lakes (North America)2
- Great Plains.2
- Gulf States2
- Gulf States.2
- Iowa2
- Iowa.2
- Kentucky2
- Kentucky.2