Found hovering around some flowers. Captured, chilled, posed, and released. I did not record the length, but it was pretty large, about 15 mm long or maybe more. A really neat mimic of a hymenopteran.
This fly appears to be the same as the "wasp-mimicking hover fly" in Castner, p. 147, fig. 545--photo. (1)
Dr. Castner does not have the species identification for that particular image handy (personal communication).
Compare to another specimen, same location, same season, four years later: