Observation: Hatcher Pass

Location: Lower Eldorado Bowl Moraine, Microdot Ridge, Cross Hill

Route & General Observations

Our class split into 3 groups and to three different areas (Lower Eldorado Bowl Moraine, Microdot Ridge, and Cross Hill) for our field observation day.

Red Flags
Red flags are simple visual clues that are a sign of potential avalanche danger. Please record any sign of red flags below.
Obvious signs of instability
Recent Avalanches?No
Collapsing (Whumphing)?Yes
Cracking (Shooting cracks)?No
Observer Comments

The only obvious sign of instability was one whumpf in a facet garden in the alders on the flats below the lower moraine of Eldorado Bowl.

Weather & Snow Characteristics
Please provide details to help us determine the weather and snowpack during the time this observation took place.

Partly cloudy
Calm to light North wind
No precip

Snow surface

Our class split into 3 groups traveling to 3 different locations:

Lower Eldorado Bowl Moraine: We found new light dry snow on top of near surface facets. The snow surface underlying the new snow was in many places waves of faceted out old strastrugi that no longer formed any slab. We found 0.5-2 cm wind crusts in several locations.

Microdot Ridge & Cross Hill: Widespread 1-2 cm wind crusts on Microdot and Cross Hill. Southerly aspects had more wind crusts and northerly aspects had more near surface facets. Widespread dust on crust conditions.


We dug pits in 3 location. The snowpack in all locations consisted of the varying surface layers mentioned above, over a "slide for life" hard layer, over weak facets, over a thick, harder slab, over more weak facets, over compacted and hard basal facets, sitting on top of weak facets at the ground. Thinner spots in the snowpack contained more well developed cupped depth hoard and thicker weak, faceted layers. Inversely, the deeper spots in the snowpack contained only basal facets at the ground, and far less developed weak faceted layers overall. Deeper areas were generally characterized by much thicker hard slabs sitting on top of basal facets.

The structure, propagation potential, and strength of the snowpack in each location is characterized below.

Lower Eldorado Bowl Moraine:
HS in pits ranged from 30 cm - 120 cm, with most pits in the 50-70 cm range. NE Aspect. 30-35 degree incline.
Variable strength ranging from high to low. In locations were we did get collapsing in our CTs we saw Q1 results. Collapsing was either occurring in depth hoar at the ground, or on the faceted layer immediately above a dense pencil hard compressed faceted layer sitting over depth hoar.
Low propagation potential.
Poor structure.

Microdot Ridge:
HS=155cm. SW aspect. 25 degree incline.
Generally strong snowpack - failure at basal facets and facets 50 cm down in facets above dense P hard compressed basal facets.
Low propagation potential.
Moderate structure.

Cross Hill
High strength
Low propagation potential
Good structure on SW aspects (completely right side up with softer layers on top and harder layers on bottom). Moderate structure on NW aspects.