Eastern Alaska Range (Deltas)

Eastern Alaska Range Snow Observations

A small fraction of terrain frequented by backcountry travelers has a professional avalanche forecast available. For this reason, the Alaska Avalanche Information Center encourages users to share what they see.Deltas mapThe Delta Range (Eastern Alaskan Range) accessed from the Richardson Highway between Paxson and Donnelly Dome is a fantastic winter playground.

This is a data-sparse area; shared observations create an ongoing history of snow and weather that can help recreationists plan and prepare for success in the backcountry. 

Please contribute your avalanche, snow and weather observations in the comments below or on the EARAC Facebook page!

Any contribution is a good contribution! Simply sharing a photo from your trip gives other users useful information. How was the snow? Was there a fresh dump? If so, how much? Where were you when you took the photo or swam around is waist deep pow?

Any information helps other users be more informed, able to make better decisions, and ultimately stay safe.

natalie ski summit lake
snowmachines near summit lake

If you have suggestions for links or improvements to this page, please email contactearac@gmail.com

Area Links
Other helpful links:
Slope Angle Maps creates a map like this to help you recognize avalanche terrain and plan routes. The slope angles are averages – ground truthing and cross referencing is still necessary.



Recent Observations from the EARAC Facebook Feed (Click the blue Date link for full post):

Triggered a good size avy last Saturday skiing on this north facing slope just north of Summit Lake. Wind slab over tundra. Went fast and carried about 1500-2000 feet.

Posted by Michael Helkenn on Monday, 16 November 2015

A close call in the Eastern Alaska Range this weekend. Photos from Ben Anderson. More information to come…

Posted by Eastern Alaska Range Avalanche Center on Monday, 16 November 2015

I do not know the correct terminology or have the snow science tools to correctly describe the exact conditions. Trust…

Posted by Jerry Lee Sadler on Thursday, 12 November 2015

28 thoughts on “Eastern Alaska Range (Deltas)

  1. Saturday November 14, 2015 1045am Isabel Pass 3100′
    Broken skies, calm, -21C (-6F), no precip
    Height of snow 29cm, foot pen to ground
    Snow surf temp -23C
    Snow 20cm down temp -18C
    Small surface hoar over three layers of fist-4F faceted old snow 1-2mm.
    No slab in wind protected areas.
    Coverage barely adequate for riding. Summit Lake still thin with some open spots.

    North of and at Rainbow Ridge and upper elevations: light to moderate north wind since Nov.11 has blown ridges bare in places with lots of gully loading. Suspect windslab.

  2. A skier remotely triggered a small storm slab avalanche while skiing yesterday @ 63.2324N, 145.3565W. 140 degree aspect, ~35 degree slope. The crown was ~50m wide and looked to be about 20-25cm, this is consistent with the depth of fresh snow from Thursday-Friday snow showers. Very low energy slide that only traveled ~30m. Not enough debris to bury someone but enough to take you off your feet. Would have been consequential if the skier were caught and was above exposure.

    We had dug a pit ~100m away before skiing and had no reaction on the ECT column test. Was able to get the column to break on a rain crust ~60cm down by prying on the column. 150cm of snow at the pit site with a 33 degree slope angle and 140 degree aspect.

    This was a good reminder for us how variable the Deltas can be. We suspect the slide occurred at a buried patch of surface hoar that developed during last weekends clear skies. I’ll post a picture of the slide later this afternoon when I get back to my camera.

  3. Avalanche reported in Rainbow Basin May 17, 2015: “From what I heard they hiked up the ridge on dry ground until they reached the top of the small snowfield, the first person to step onto the snow slipped and slid several feet, releasing what appears to be a wet loose slide. He slid with it for a while, luckly because he was in the back of it got left behind. He said it was icy where he stopped and when he tried to stand up he actually slide further down, into the debris. They said it ran on frozen/icy moss and rocks around 4pm. The weather had been very warm and sunny and the slope is facing northwestish.”

  4. Hey all,
    I know this is a bit late but I figured it’s better to have old info than no info!

    We spent a few weeks on the College Glacier on the south side of the Range from March 17th to March 31st. Conditions were better than expected with firm playful powder on N-NW aspects. As conditions warmed and a few small snow events moved through, all aspects became prime.

    We dug a few pits over the course of our time up there and found a stable snowpack. Pit elevations varied between 5500′ and 6500′ and multiple aspects. Total snow depth varied between approx 200cm and 350cm. There were some weak layers typically about 15-20cm (CT12-15) below the surface but they did not propagate in our ECTs (ECTN12-18). The snowpack seemed very right side up for the first 130 to 150cm or so. Deeper than that, there did seem to be some layers that could be problematic, but they were too deep to be reactive to our ECTs and CTs. For our skiing purposes, it seemed like a low risk, high consequence situation. The hard ice/rain layers that have been so prevalent north of the pass and at lower elevations were non-existent in our profiles.

    Towards the end of our stay we did start to see a good melt/freeze crust forming on slopes with more southern aspects. I imagine that trend will have continued after we left.

    Sorry for the rather scattered summary. If anyone feels the burning desire for more specific pit/test observations, send me a message. Have fun and be safe out there.

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