okc do what an outfitter once told me to do when getting ready for a highland hunt, jog with a plastic bag over your head!!!

I live at a mighty 380ft above sea level. When I hunted in the Gila in NM the altitude was "only" 7k-9k but it still nearly killed me and I was in my 20s and had actually joined Golds Gym and started training the summer before the hunt. I just am not sure you can EVER really train for the lack of oxygen, lol not unless you wear that bag over your head ALL the time.

As was said, keep well hydrated. Water helps keep oxygen in the body and if you get dehydrated it basically doubles the effects of oxygen starvation. Cardio is really the key if you are otherwise healthy. Anyone can walk miles and even jog to get their body in generally good shape. But without a superfit cardio system, you just aren't gonna be able to do anything!
RA