Elk Mountain

We visited Southern GNP to take a closer look at very large avalanche that failed during the weekend Atmospheric River.

• This natural hard slab avalanche occured on a wind-loaded SE slope at 6600'
• The crown depth varied wildly across the slope:  in a distance of only 10 feet, depth increased from 8 to 36 inches.
• The failure plane was a thin faceted crust.
• Further downslope the slide "stepped down" to a deeper weak layer.
• We felt small collapses as we climbed between 5100' and 5300' on a SE slope. 
• On sheltered mid-elevation slopes, snowfall from the AR was 6 to 10 inches.
• The top 4 inches of the snow pack was moist to wet up to 6500'

We skied the bed surface, traveling one at a time. 

Small collapses as we climbed 5100'-5300'. Minimal cracking in wind-drifted snow.

@ 6600' SE (windloaded slope, avalanche crown)

• HS = 300 cm
• Failure plane down 85 cm on 4F faceted crust (2/22?)
• Other facet layers down 115cm (2/13?) and 135 cm (1/31?)
• Snow pack otherwise is P to 1F