Small bee, abdomen dark with stripes of white hair, on Solidago gigantea flowers. Ruderal floodplain community with Kochia scoparia, Chenopodium simplex, Chenopodium berlandieri, Helianthus annuus, and Cleome serrulata. Midday to early afternoon, sunny, 66 F to 73 F, gentle to fresh W breeze, good air quality.

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

Short tongue; eyes not parallel in front-on view and generally did not match the appearance of Andrenidae. Second recurrent vein S-shaped, pointing to Colletinae. In Montana, the only genus in this subfamily is Colletes.