...which one? I'm fairly convinced this is myrmeleontid, and not a "skinny dobsonfly" like I had originally thought. Scotoleon, Myrmeleon, and Brachynemurus all seem like options.

Observed at night in a mixed chaparral / grassland area in Oakland, CA, USA, along with many others. ~2-3 cm total body size.

Update: ID provided by John Oswald on BugGuide.