Unsure of species. Have never seen a bee with a white tail here. Maybe a Bombus sandersoni?
Foraging in the wet margins of the creek for minerals etc.?
2 short videos available. It was windy and the bee was grooming itself in a corner. Seems like the very very tip of the abdomen was darker, possibly black. Elevation 5100 in a cirque.
sorry, Linc, but the dry cycle maimed it.
Feeding on Ceanothus and Lupine and buzzing around very quickly.