Gear
Western Mountaineering Bison GWS
Severe cold with wind, spindrift and condensation risk
Expert reviewed
Topic summary
Severe cold with wind, spindrift and condensation risk
Key takeaways
- 850+ fill-power down
- GORE WINDSTOPPER shell
- expedition draft control
- Outstanding loft, workmanship and protective shell performance from a company known for conservative cold-weather design.
Verification notes
Evidence: expert reviewed. Last verified July 16, 2026.
Editorial take
Western Mountaineering Bison GWS is a cold-weather sleeping bag with an advertised -40°F rating and 850+ fill-power down; GORE WINDSTOPPER shell; expedition draft control. It is best suited to severe cold with wind, spindrift and condensation risk.
Not ideal for
- High cost and significant packed volume.
Loading…
Verified specifications
- Key features
- 850+ fill-power down
- GORE WINDSTOPPER shell
- expedition draft control
Warranty and repair information: contact Western Mountaineering directly for the most current terms.
Related
Related skills
Related field guides
Related adventures
Loading field test report…
Loading reviews…
Data sources & verification
- Last verified: 7/16/2026