- West (U.S.) 35
- Colorado 33
- Rocky Mountains 32
- Colorado Springs (Colo.) 25
- Arizona 17
- Montana 17
- Utah 16
- Wyoming 16
- New Mexico 14
- North America 14
- text 55
- moving image 17
- still image 15
- sound recording 9
- cartographic 1
- mixed material 1
- videorecording 16
- conference publication 15
- graphic 12
- speech 11
- biography 2
- letter 1
- map 1