If your in Northern Colorado I would think this late in the season just clean the lot mechanically. I'd be surprised if you see much more weed germination this late in the season. Next spring prior to weeds popping apply Mojave Herbicide at a rate of 15 lbs to the acre. You could tank mix with glysophate if you have some early germination. I would recommend adding a tracker dye to the mix when spraying sterilants.
The Arena, the Field of Battle, the site where the fight actually takes place is our own heart and all of our Inner Man. The time of Battle is our whole life.