For the past 6 years I've used a Mountain Hardware Phantom 850 down fill bag. I've hunted in CO at altitudes from 10,000 to over 11,500 ft. in late Oct and early Nov. I've never been too uncomfortable using the bag. It is also easy to ventilate when it get's too warm, which is usually the case when using my SO Tipi and Ti stove.


Start young, hunt hard, and enjoy God's bounty.