Taken at the western edge of the great plains/ Rocky Mountain Foothills transition at ~ 5500' elevation. March 17 is extremely early in the season. Plants are dormant.
The identity of this beetle is real mystery. We've done a lot of searching. What it looks closest to is a member of the Ciidae, Dolichocis manitoba, illustrated on p. 409 of Arnett et al, American Beetles, Volume 2. Members of this family are mostly tiny, maybe 2-3 mm, but do range up to a maximum of 6 mm for some species. Shape of the pronotum, clubbed antennae, shape and texture of eletra, even tiny hairs along margins and apical ends of elytra all match. However, the tarsi on our beetle are more elongate, although the tarsal pattern is 5-5-4. I will submit two other images. Any help with solving this mystery will be much appreciated.