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Dec 11

How Often Does Marble Peak Avalanche at Full Path?

Someone brought this up the other day. Now that Marble Peak is skied so much, it doesn’t seem to produce full-path avalanches. That could change if we get some kind of unusual series of storms that close the road and build up a 2+ meter snowpack. But for now, parking at Lumber Curve within the Marble Peak avy path (where the Anthracite Pass trailhead is) is a workable solution.

We were around the first specifically known time Marble Peak slid full path, February 1995 (reference, Colorado Avalanche Information Center 1994-1995 Annual Report). This class 5 avalanche took out a mature spruce forest above the road, extended the runout into mature aspen forest by 300 feet, and improved the skiing immensely. Quite impressive for an avalanche path that’s not really big in topographical relief, at only around 2,500 vertical feet if you count the runout. What’s interesting is not only did the big one get turned by terrain features, but it ran an impressive distance on lower angled terrain below the road. Google Earth tells the tale.

This long return period avalanche (LRP) occured during a week-long storm cycle that brought the snowpack in the Yule Quarry region to more than 7 feet (84 inches) on the ground (possibly 8 feet in places), with a water equivalent of about 7.3 inches.

According to comments on this post, that have jogged our memory, the Marble Peak path ran full-path again in 2005, during the same cycle that shattered a mature aspen grove on what’s known as “Pre Mud,” the slope just before Mud Gulch as you’re headed up the Yule Quarry Road. Indidentally, the huge 2005 Cleaver slide off Chair Mountain also ran at this time.

What’s the takeaway? Until the snowpack gets quite deep and unskied, in our opinion parking at Lumber Curve is less risky than driving highway 133. But be aware of trends. When the snowpack gets quite deep (we’d define that as more than 6 feet, 72 inches on the ground) and unstable, the Marble Peak path could go big.

At this time (January 2017) we may be approaching that situation.

4 comments

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  1. Jon Fredericks

    Good post topic. I believe the last time it ran full path was the big january storm of 2005, when the spruce/fir tree island and anthracite trailhead signs were “re-located” to the valley bottom. That particular storm dropped around 7″ of water in a three-day period. The mud gulch slide was quite impressive from that storm, as was the “horn” slide path on Chair mountain. Both of those paths cleared many new acres. Please correct me if I am mistaken.

  2. Editor Skier

    Hi Jon, we did some research and we’re pretty sure that the class 5 slide that took out the forest and extended the runout of the Marble Peak avalanche path was the one in February of 1995. Source cited in updated post above.

    More recent slides did “relocate” the trailhead sign etc but the forest removal occurred during the earlier huge slide as best we can tell from both memory and documentation. The other indicator is that the fallen timber that’s left from the mature forest removal now appears very old, a lot more weathered than just ten years.

    That said, your point is well taken. When the snowpack gets up to around 7 inches of water, and hasn’t been skier stabilized (such as during a big storm cycle when skier traffic is reduced or eliminated), look out! A few other larger slides have indeed occurred over the years, but none have gone “full path” as defined by the 1995 LRP.

    As we’ve already got 50+ inches on the ground above Quarry Road at around 10,000 feet, and 55 inches was the starting point during the 1995 storm cycle, we are clearly set up for the LRP to happen again if we get another big storm cycle. Interesting to watch — and be careful of.

  3. Jon Fredericks

    Thanks for clarifying. I have a collection of impressive photos taken (1/20 & 1/21/05) of the Marble peak path after that particular cycle, that I would be happy to share. Maybe the 2005 cycle just knocked out the last of the tree island – finished it off, so to speak. This was the same event that blew out the aspen forest to the north of Mud Gulch above the road. It was quite an impressive display overall. We also took some great post-slide photos of the cleaver/horn: http://avalanche.state.co.us/caic/acc/acc_co.php?accident=20050112

  4. Editor Skier

    Hi Jon, thanks so much, we’ll edit this post to clarify. Sounds like we had a 10 year LRP on those Marble Peak full-path slides. Now the question is, does the amount of skiing make any difference? This winter will be a good one to watch as it appears we’re getting the requisite snow depth for such slides, so we’ll see which ones happen.

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