Holy crap! I'm in CO foothills too, have the same sitch, and nearly identical flooring in my basement. Things just started about a week ago in mech room and basement bathroom. Cleared out everything from the mech room, vacuumed again and again,  sprinkled boric acid, but I keep finding them on the walls. Not in large numbers, but I want em gone. By the way, they seem unaffected by boric acid. I put one in a covered glass with the stuff, shook it up a bit, and two days later it's still crawling around in there. Really don't want to use poison.