Rocky Mountain National Park, Larimer County, Colorado, USA August 6, 2014
This Bombus species was found on the Upper Ute Trail, elevation about 11,800 feet. Several of these high elevatiion Bombus are very difficult to separate. Possibly B. frigidus based on T3 being entirely black and the thorax bands more sharply defined than in B. mixtus? Any help with its ID is greatly appreciated.