Ryan,
Assuming you are hunting public land during Colorado' s 1st Elk Only season I' d recommend:
(1) Arrive early, acclimation prior to the heavy exertion of elk hunting is VERY helpful and even if you have to leave a day before the season is over, it is FAR superior.
(2) The first two/three days of that season will net you 90% of your results (weather and luck being equal). Plus don' t be surprised if by day 4 that you may have had just about all the fun you can stand.
(3) If you can arrange it to sleep one night on your way driving in at around 6,000 to 7,000 feet and then meet with your outfitter the next morning and then spend that next night at (I' m guessing) 9,000 to 11,000 it will help you lot.
(4) No alcohol and No heavy exertion in the first 48 hours is highly recommended.
(5) Keep water easily available all the time especially in the first 48 hours and drink until you whiz like a race horse.

Side note: There is a herbal remedy (lab tested, double blind pharmacuetical test, the whole bit) that essentially pre-empts altitude sickness.

Even so, arrive early --- that season, the first two days are KEY, KEY, KEY.

Best Regards,
EKM

Arrive early, you can' t hunt if you are sick.