Avalanche: Chugach State Park

Location: South Fork of Eagle River, Hiland Road, Cottongrass Path

Route & General Observations

Large natural and human triggered avalanches continue throughout the South Fork Valley. Travel on terrain near slopes steeper than 30 degrees is discouraged. This instability will be very slow to stabilize.

Avalanche Details
If this is an avalanche observation, click yes below and fill in the form as best as you can. If people were involved, please provide details.
Trigger NaturalRemote Trigger0
Avalanche Type Soft SlabAspect Northwest
Elevation 4000ftSlope Angle 35deg
Crown Depth 24inWidth 3000ft
Vertical Run 2000ft  
Avalanche Details

Cottongrass Path ran naturally on 3/16/18 and nearly reached Cottongrass Road and adjacent houses. This slide path has killed skiers in the past. Over 30 major natural and human-triggered avalanches have occurred in the South Fork Valley over the past two weeks and likely will continue for the foreseeable future. Backcountry travel on or adjacent to any slopes in excess of 30 degrees is strongly discouraged.

Red Flags
Red flags are simple visual clues that are a sign of potential avalanche danger. Please record any sign of red flags below.
Obvious signs of instability
Recent Avalanches?Yes
Collapsing (Whumphing)?Yes
Cracking (Shooting cracks)?Yes
Observer Comments

30 major natural and human-triggered slides are now visible along Hiland Road. This is one of the most extensive and sustained avalanche cycles on Hiland Road in the past 20 years. Slides have been occurring on E, N and W facing slopes above 2,000' elevation and on slopes as low as 30 degrees. Human-induced collapsing is triggering avalanches at distances of 1/2 mile or more from slopes that are steep enough to slide.

Weather & Snow Characteristics
Please provide details to help us determine the weather and snowpack during the time this observation took place.

Roughly 50% of the snowpack thickness in the South Fork is comprised of faceted crystals that are resulting in widespread collapsing and propagating failures. This snowpack configuration is extremely resistant to strengthening through compression and will remain unstable until it melts. It is likely that this snowpack configuration extends to other Chugach Front Range Areas.

Photos & Video
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