There ain't much game in WA above 8000'. Reduce that to ~6000' in AK. The spine of the rockies is unique in regards to game at elevation.
Ability to work at elevation has a large adaptation component to it. I schooled in Bozeman (4800') and traveled from there to play a ball game in Laramie (7200') at it was rough for us. Can't imagine coming from the coast to play there. I can throw things into saltwater from my back patio, and as such, hunting in MT this fall at 9000' was rough at first, but noticeably less rough a few 3000' gain days later.
Takes about 6wks to mostly adapt to altitude. You get most of the way there in 2wks. A good guideline is your resting pulse lying in your fartsack relaxed. Mine is always in the mid 50's. At 8000ft in MT summer before last it was in the low 80's after gaining altitude most of that day.
No doubt there's an adaptation component to altitude. That doesn't change the fact that most people's cardio capacity will be taxed or maxed at altitude, and the better their cardio conditioning, the better they'll do.
