Spent 3 days traveling into the N Fork of Bridge Creek via Maple then Last Chance Passes. Exited via the PCT to Rainy Pass.
We were able to observe the impressive recent cycle in some remote parts of the N Cascades, and found signs of lingering instabilities with windslab and deep slabs.
Many, but not all large avalanche paths produced D3's that ran full track to their historic runouts in valley bottom early during the last AR, with smaller wet avalanches running to top of runout zones later. Most notably, south facing paths in Maple Creek (SE side of Corteo Pk) and in Bridge Creek (S Side of Frisco Mtn) ran very large with what looked like dry snow at the time, though evidence had been largely settled out and difficult to discern in some cases.
Slopes on N aspects were often windsept and faceted above the rain line of about 5,800ft. We found scattered, recently formed (and some still forming) wind slab of Pencil hardness, sometimes resting over much weaker facets-whiched turned us around from our objective at 6,500ft on the 9th. Some natural windslabs had pulled out in the D2 range likely on the 7th or 8th in the same area.
On our way out on the PCT we saw a recent (within 1-3day) deep slab on an eastern lobe of the Sandalee Glacier on the N side of McGregor Mountain (HS-NC-R1-D2.5-O). Looked like a chunk of cornice fell off and triggered it. The same bowl held an older deep slab release, to lookers R in the photo.
Slopes up to 6,000ft have a rain crust from early March. The crust is thin, especially on shaded open slopes 4,000- 5,500ft. Facets have formed above and beneath it of F hardness on shaded slopes. In the canopy and lower elevations the crust is often much thicker and without new or faceted snow on top.