Observation notes: These small (2cm or so) butterflies congregate in large numbers (dozen or more) and flutter close to dirt or muddy ground. The photographs show them with wings open and closed. Weather was warm (~27C) and dry.
Verified by: A_baldini
Verified date: July 03, 2019
Coordinator notes: These are Rocky Mountain Dotted-Blues, Euphilotes ancilla. The Boisduval's Blue and Blue Copper are both larger, entirely lacking orange coloration on the ventral side. They are abundant in most of Colorado's foothills and mountains in June - early July.