We are not 100% sure but we believe this is the California Broad-necked Darkling Beetle (Coelocnemis dilaticollis). It’s easy to see where this large, flightless beetle got its name. Broad-necks are common under loose bark in dry forests in southwestern Canada and the western US. Adults are fairly long-lived, living up to three years, and hibernate in small groups in dry, sheltered situations. While we couldn’t locate specific diet information for this species, members of this genus eat a variety of plant matter, including whole grains, lichens, and fungi.
Photo by: Rose Marchak on 6/19/21 in Missoula, MT