Antimidation and I have been collecting recently in China Camp in Marin County just outside of San Francisco. We're seeing a majority of Camponotus with smaller populations of Formica, Messor, Crematogaster, Aphaenogaster and loads of termites which we are sometimes capturing as food items. We have also seen about 500 scorpions when turning logs and rocks.
Collected - +38° 0' 31.00", -122° 30' 0.00"
The area was dry and slightly elevated beneath oaks.
The queen was nesting in hard soil though most nests of the species are in rotting wood. They do not seem to nest beneath the wood in soil in large nests.
I've added some photos of her and her workers in hopes of a full id. Please let me know if you need more photos of specific regions or additional details for an id.