Location: Western foothills of the Cascade range. Altitude of collection 3000-4000 feet, near Oakridge Ore.
Habitat: Edge of clearing, nesting in dry, rotted out stump. Some nest material, typical of thatching, dry pine needles. Not a large mound, just some dried needles near the base of the stump. Majority of ants were warming up on the inside of a sheath of bark facing the sunshine.
For the rest, see the pictures.
Size, large workers. This one is 8-9mm (was the biggest one I could see).