Pediocactus simpsonii
I found up to a dozen or more individuals per square meter along the road at the high pass of Utah Highway 72, Fishlake National Forest, UTAH. They are low and inconspicuous - one may not notice them when not in flower. Soil is very rocky and volcanic in origin. At this elevation (~2736 m or 8975 ft), they undoubtedly spend months under the snow - unusual for a cactus! At this pass, a spectacular view to the east presents itself (San Rafael Swell, Capitol Reef, LaSal Mts., etc.). May 2013.