Northern Madison

Toured into Beehive Basin on 04/05/2024. Light freeze overnight ~0.5" crust with wet snow below on most slopes. Treed areas did not freeze. Clouds along with a cold south wind kept many slopes from softening. By 11:30 sunny slopes below 9000' had become wet and made for poor ski conditions. Attached are photos of recent loose wet avalanches that likely happened 24-48 hours ago. All attached photos on SW-W aspects at ~9800'

We toured down the west side of the Bridger Range on the edge of Truman Gulch and found predictably weak snow on an upper-elevation NW-facing slope. Conditions were variable and transitioned to a thick crust as we moved on to a lower elevation, west-facing slope. By the time we came down the Ramp, the snow was getting wet, we saw roller balls, and we avoided steep, sun-exposed terrain. 

We dug below NW Passage. It was a 135 cm deep snowpack, dry throughout, with Fist plus hard facets and depth hoar making up the foundation (ECTP30, PST 42/100 end at 30 cm from the ground. 

We rode from the Buttermilk trailhead up Denny Creek to Lionhead Ridge, along Lionhead Ridge through Watkins Creek and to the motorized boundary at the head of Targhee Creek. 

There was a ~1" crust at the surface when we left the trailhead, with dry snow beneath. We saw our first wet loose avalanche of the day running around 11 am. By 12:30 there were dozens and many rollerballs. None of them ran particularly far or picked up too much volume.  The snow surface was moist on sunny slopes by late morning, but not more than a few inches down.

We saw one small slab avalanche that occurred since this weekend's snow. It appears to have been triggered by a snowmobile yesterday (4/1/24). It broke 10" to 2 ft deep, 50 ft wide, and ran ~50 vertical feet. It broke on a thin layer of facets beneath the new snow. Digging in the crown, dry facets at the ground were along still present and weak (fist hardness).

Signs of older avalanches were visible beneath the new snow, including one slide that broke in early March. No cracking or collapsing were observed today.

From email: We were out camping around the east side of Sphinx Mountain. We rode sleds over dirt for a while and came from Buck Ridge. We didn’t see any fresh avalanche crowns all weekend. We did get a big whoomph that collapsed the snowpack while skinning along a ridgeline on Sphinx that seemed freshly loaded. Cracks shot out maybe 25 feet around, but it didn’t move. We didn’t dig snow pits; we followed our plan of keeping our terrain selection on the mellow side.

Today, myself and 5 others toured up beehive basin for an avalanche 2 course. In the morning a pit was dug in the bonus wiggles on a south facing slope. The biggest takeaway from this was the melt freeze crust on the surface. This pit experienced an ECTP-22 and CT-15-Q1. Both tests failed on depth hoar 40 cm above the ground. Another pit was dug on an east facing slope on the west side of beehive basin in an opening between tree fields, about 30ft from the ridge line. The biggest takeaways from this pit where a PST 40/120-end at the surface hoar-melt freeze crust interface 40cm above the ground and ECTN on the upper crust. As for the surface, the surface crust softened for the afternoon decent. There was little to no wind today and no evidence of wind slab, no observed avalanches, and no observed cracking or collapsing.