This is a list of the states with sites that were sampled. 

Arizona - Navajo National Monument
                  Oregon Pipe Cactus
                  SNM

California - Clark Mountains
                     Death Valley National Park
                     Fort Irwin
                     Joshua Tree National Park
                     Mojave National Preserve
                     Silurian Valley

Colorado - Colorado National Monument

Idaho - Idaho Sites
             Kuna Butte

Nevada - Great Basin National Park
                 Nevada Site

New Mexico - Carlsbad Caverns National Park
                          Cebolla Wilderness
                          Fort Bliss
                          Holloman Airforce Base
                          Jornada LTER
                          Sevilleta LTER
                          White Sands

Oregon - Oregon Trail

Utah - Arches National Park
            Canyonlands National Park
            Desert Experimental Range Station
            Dugway Proving Ground
            Hurricane
            Natural Bridges National Monument
            San Rafael Swell
            Unita Basin
            USPC
            Zion National Park

Washington - Horse Heaven Hills