Found near the summit of Mill Hill patrolling over dry Garry Oak meadow habitat. I knew this was a bumble bee mimic hoverfly and initially I thought its pattern was mimicking Bombus occidentalis. I can see now that it probably matches either B. californicus, B. vosnesenskii, or B. caliginosus better. Regardless, it took me a while to figure this one out and it appears to be a scarcely documented species. I never saw it land in the 20+ minutes that I followed it around, so I was only able to get poor images of it in flight. I am fairly certain of the identification based on information found in the Key to the Genera of Nearctic Syrphidae by Miranda et al. I believe you can see the medial black face stripe and, when it's in profile, the concavity of the face, which are features that separate it from Hadromyia grandis.