| Recent Avalanches? | Yes |
| Collapsing (Whumphing)? | No |
| Cracking (Shooting cracks)? | No |
Observation: Portage / Placer
Location: Byron Glacier Trail
The last 1/8 mile of the established trail is covered in avalanche debris that released from both sides of the valley. The entire Byron valley is full of avalanche debris from the huge avalanche cycle that occurred in mid March. A series of storms from March 7th-24th dumped 27″ of rain at the Bear Valley (Portage) DOT RWIS weather station. This amount of rain is equivalent to ~30+ feet of snow in the upper elevations. There is still a very large cornice and a lot of snow in the upper elevations that hasn’t avalanched yet. Avalanche activity is expected to occur in the Byron Valley well into the spring due to sun, above freezing temperatures, and any rain. Unless you have avalanche rescue gear, advanced training and knowledge to evaluate an avalanche hazard we recommend avoiding Byron trail until summer. Byron Glacier Trail has had several near misses with hikers running away from avalanches in the spring and one fatality due to a snow cave collapsing.
Obvious signs of instability
Observer Comments
Its hard to tell when the most recent avalanche occurred, likely over this last week with such warm temps and sun.
We measured the runout distance of where the debris initially crosses the trail, just before the first bridge. The runout distance was 36 degrees looking up at the starting zone on the SE facing slopes and 34 degrees on the NW facing slopes.
Weather
Clear skies
Winds were 10-15mph
Temps upper 30Fs
No new precip
Snow surface
Firm and supportable melt/freeze surface
New avalanche warning sign at the trailhead for Byron
This map outlines both the area of avalanche debris following the March storms and it also shows how much avalanche terrain (colored pink) is directly above the trail.
This is somewhere near the end of the trail with debris filling the entire Byron Valley
Debris, broken alders along the trail with the NW facing terrain in the background. This area still has a very large cornice and a lot of snow in the upper elevations that can still avalanche.
Looking up at the cornice.
Debris, broken alders covering the trail with the SE facing terrain in the background.
This debris will be the next generation of snow caves as Byron Creek flows and melts out in the summer. This is another dangerous hazard to expect into the summer when the avalanche danger goes away.