First off- Good Luck in Colorado. If you have never hunted the west you are in for a treat. Its where i wish i was all the time. As for altitude sickness it takes effect on people differently. Tums, Rolaids and water i have heard of( water is the best). I personally am lucky enough to have grown up hunting/living in high alts and have a built up muscle memory of sorts which helps when i get to leave the east and hunt out west. As far as a good option i suggest getting there a day or two early, if you can. Maybe rent a hotel in Colorado Springs or Denver or somewhere. There are a lot of hiking trails you can go hike between 6 to 10k right by both cities that will help you adjust better when you actually get there. The first few days are the roughest and if you get that out of your way before your hunt, you will do much better. I took my girlfriend hiking this summer, she has never left the east coast in her life. I took her to Colorado springs, the first few days she was struggling, but by day 3 she was moving good, keeping up with me and my friends that live there full time. Granted we work out about 5 to 6 days a week year round, being in shape is HUGE!!!