If you've done Deadwood 1 and 2 this is a gift: you know exactly what to look for. It is hidden in plain sight. You will know it just a soon as you see it.
Hidden along the popular Bartell Trail in the Palmer-Bartell Forest. It is an authentic Geocache Preform Container ("test tube") with a Rite-in-the-Rain (RITR) Logbook and a couple of pencils (but always good to bring your own). The "test tube" itself is placed inside another appropriate container or carrier to blend in with the surroundings.