My suggestions are a little different and spread out a little. I agree with advice above and being in shape is good advice however weather here in Colorado can be a challenge to even get to a hunting area. 3rd season in Colorado you should expect snow and cold weather. It depends on the year and where you are going, access and elevation. I would say my first thought is getting to and from your hunting area which usually means 4 wheel drive and having good tire chains for all four wheels would be high on my list along with a shovel, tow strap etc.. Expect mud and snow! It might be important to not only get into your hunting area, but out of your hunting area days later. Second would be your type of camp. (Motel, RV, Tents, etc.) Motels might work out, but if in a tent I would want a camp that can with stand heavy snow, wind and cold weather. Along with that is a good cold weather (zero or greater) sleeping bag. Even in an RV type camp I like a good cold weather sleeping bag. I have experienced a dead camper battery and a furnace that would not run and a truck that would not start because of the cold. Next would be warm and cold weather boots that are good in steep terrain and comfortable to hike in. After that I bring clothing to match the possible weather conditions, good sighted in rifles, scope caps and a pack with essential survival gear. Good luck and enjoy your adventure!