I found this beetle flying around some purple thistle on my recent trip back to Northern California. He is a pretty common specimen, a soldier beetle (family Cantharidae). Soldier beetles are elongate, soft-bodied beetles that reach up to 15 mm in length, and are similar to lightning bugs, but their head protrudes beyond the pronotum (shield-like structure on the thorax) and they do not have light-producing organs. Usually the adults are found on flowers, and the larvae are predaceous on other insects.
Coleoptera; Polyphaga; Elateroidea; Cantharidae; Pacificanthia consors
Common Name: Brown Leatherwing Beetle
Here is another picture of a cantharid beetle, but it is Cultellunguis perpallens sanctaeclarae thanks to the good people at bugguide.net - it appears they have some soldier beetle experts there, to get it down to subspecies.