This gray, white, and black patterned species of sphinx moth can be found primarily in the western part of the US (from British Columbia, south to CA, and as far east as TX). It frequents mountain woodlands and prairie stream valleys. In western Montana, it can be found in June and July. The adults fuel up on nectar from flowers, while the larvae feed on snowberry.
Photo by Kathy McEldery on 6/27/20 in Plains, MT.