Denali, Aconcagua, Himalaya… mountaineering in its extreme sense. These are places where mistakes cannot be made and so the Bison is most often chosen to serve. The Gore Windstopper™ fabric makes this bag impervious to the elements while remaining lightweight and very compressible with a rating of -40f.

Crammed with 42 ounces of 850+ fill power down this bag has 10 abundant inches of heat-trapping loft. Huge V-Block Side Baffles and horizontal baffles across your chest keep the down fill in place. Double Interlocking Draft Tubes and a down-filled Gore Windstopper™ collar seal in heat and security while howling winds surround your tent. The massive hood is not only well filled but is completely made with Gore Windstopper™ fabric and has a large integral hood ruff to seal your face from the elements.

The Bison is the crowning glory of Western Mountaineering and demonstrates our commitment to innovation and quality. This life-saving bundle weighs in at a scant 4 lb. 10 oz.