Couloir
A steep, narrow gully or gorge carved into a mountain face, often flanked by cliffs and offering committing off-piste descents.
Couloirs are a signature feature of steep skiing. They funnel snow and skiers between rock walls, are usually north-facing where snow holds best, and range from wide open runnels to no-fall zones only a couple of metres wide.
Because they collect wind-loaded snow, couloirs are also common avalanche terrain - a classic assessment challenge for freeride and ski-mountaineering skiers.