The mission is grand, and the conditions are bleak, but the Prism shares out grit. We stuff all our gear into the cavernous body and pull the 4 compression straps tight. We slide the hip belt out, so it doesn't interfere with our fully racked harness, while the low-profile lid keeps our rope at the ready. Whether we're climbing a mixed route or postholing through knee deep powder, the light, rugged construction moves with us, not daring to challenge our stability more than the mountain already is.