I ware long johns and camo pants, good boots that are water proof and insulated, and then on top, a t shirt, long sleve t shirt, a sweat shirt, and a water proof insulated jacket. In CO. you will be walking a lot and it is easy to start sweating. That is what you want to avoid. Dress in LAYERS because it might be 12 degrees when you leave camp and 50 degrees at 2PM. I don't like insulated bibs or coveralls because you will sweat then get cold if you stop. If you take them off, you have to lug them around. I ware coveralls in camp at night but not while hunting. Thin layers is the way to go. Also, I would suggest two pairs of gloves. 1) some really good insulated ones and 2)a lighter pair for when it starts warming up. I usually bring several different types of hats too.

It is usually a drier cold here then it is in OK. I have experienced both.