Somewhat smaller Bombus with less well-defined dark central dot dorsally on thorax; abdomen mostly black and second terga burnt orange. On flowers of Astragalus crassicarpus at peak bloom on gentle E slope in native grassland regrowing from fire last fall, with Agropyron spicatum, Tragopogon dubius, Crepis sp., Poa secunda, and Phlox hoodii. Only one individual of this species seen. Partly cloudy late afternoon, light to gentle W breeze, 71 F.

Elevation ca 4000 feet. Disturbed, shrubby riparian corridor on stream restoration site within a patchwork of native and non-native grassland.

Identified based on Koch et al. 2012. Females apparently quite distinctive when of the appearance of this individual, with T1 yellowish, T2 brownish, and the other terga black. Short cheek and mostly black hairs on face are other identifying features.