Believe it or not my CO buddies gave me a great tip. Take some Rolaids & chew one up every 1/2 hr while hiking & hunting....amazing results in reducing leg cramps at high altitudes. Chapstick with sunscreen is a blessing as well.
A Camelbak or something similar to keep you hydrated. The higher elevation will dehydrate you before you know it and spoil your hunt. Chapstick was mentioned and a definite must have in your pack. Also, pack some orange flagging tape in the event you kill a critter and need to mark the trail for packing purposes.