Northern San Juan

You can trigger an avalanche where you find wind-drifted snow forming a cohesive slab over weak snow at upper elevations. Near and above treeline slopes that face northwest to north through east are the most dangerous as strong westerly winds loaded snow onto leeward terrain.

Look for and avoid steep slopes that have a lens-shaped or pillowy appearance, or slopes that look smooth and sound drummy or hollow. You will most likely find areas of drifted snow below ridgelines and in cross-loaded gullies. Cracking or collapsing in the drifted snow indicates retreating to lower-angled slopes sheltered from the wind.