This will be our 6th year Elk hunting Colorado. This year we are going a little different than usual. We will be hunting some private ground land locked with lots of public land and will be using ATV's to do our traveling to different locations. We will be between 6500-8000. We live in KY. Anyone from the east who has traveled out and used ATV's, did you have any trouble with your ATV's running good at the higher altitudes? Did you anything different before going? If you had problems, what did you do to combat them? Thanks for any help!