Ice Worm Glacier Disappears in 2023

In 2023 we determined that the Ice Worm is no longer a glacier. Ice remains, but it exhibits no signs of flow and sits stagnant in the cirque.

Ice Worm Glacier is an east facing cirque glacier on the east flank of Mount Daniel, WA. The glacier is at the headwaters of Hyas Creek, which drains into the Cle Elum River. The cirque floor is at ~1940 m and the headwall at 2050 m, there is a bench at 2150-2300 m that held a glacier/perennial icefield prior to 2015.

The glacier is fed by wind drift accumulation along the ridge that was just above the top of the glacier during the 1944-2000 period. Avalanching from the slopes below the East Peak of Mount Daniel and from the ridges extending along the north and south flank of the glacier have also been significant. The glacier is part of the Mount Daniel-Mount Hinman Glacier Complex just south of Highway 2 and sits astride the Cascade Divide. This complexcomprised of 9 glaciers covering km2 in 1984. This was the biggest cocentration of glaciers between Mount Rainer and Glacier Peak At the end of the summer 2023 melt season only three of these remain as glaciers, Daniels, Foss and Lynch Glacier. We began monitoring these glaciers along with Ice Worm Glacier in 1984.

In 1984 there were nine glaciers spread across the Mount Daniel-Mount Hinman complex. You could traverse from one to the next with limited time off snow and ice. By late summer of 2023 only three glaicers remained. We monitored Daniel, Ice Worm and Lynch every years since 1984. Ice Worm no longer a glacier in 2023.


Ice Worm Glacier Evolution

In 1986 William (Bill) Prater, who had made many first ascents in the area between 1944 and 1960, joined us in the field. Bill also had invented and patented (1973) the first snowshoe with a claw attached to its binding, the Sherpa Snowshoe. Comparing images from these early visits with the current margin of Ice Worm Glacier indicated that there had little change in this glacier from 1944-1986. The mapped area in 1958 was 0.19 km2 (Fountain et al. 2023), in 1986 we mapped the area at 0.18 km2.

Each summer during the third week in August we measure the mass balance of this glacier. Because the glacier lacks crevasses we simply grid the glaciers with measurements made 50 m apart along transects running up the glacier and across the glacier along the margins. We also completed a longitudinal profile running up the glacier from a fixed location on the bedrock at the below and at the top of the glacier. The surface elevation was determined at the specific 50 m points to identify thinning of the glacier. During the first decade the glacier extended to within 10 m of the ridge on the south side of the glacier, allowing us to ski off of the ridge. By 1995 this was no longer possible as the top of the glacier was retreating as fast as the bottom of the glacier. 

 This summer we observed a dozen holes that reached the bottom of the glacier 4-6 m below, indicating how thin the ice is. There is no movement, the size and thickness are too low to generate future movement, hence this is no longer a glacier. A glacier is a body of snow and ice that is moving, this requires a persistent thickness of 20-30 m, which is typically associated with snow/ice areas of ~50,000 m² or larger. As a glacier becomes thinner or smaller than this movement will not be sustained.

We have measured discharge at a natrual weir below Ice Worm Glacier since 1986. Average August daily runoff has declined 60% by 2022.

Field painting by Julia Ditto showing the landscape carved by Ice Worm Glacier when it was much larger in the past during the Last Ice Age. She depicts striations left by the ice, and the rounded forms in the foreground of the top image that were smoothed. Unfortunately the landscape where the Ice Worm sits is on its way to looking like this.


This datasets highlights the thinning of Ice Worm Glacier from 1985 to 2023, when it officially became not a glacier. NCGCP records the surface profile annually, so we were able to capture the thinning and change in shape from convex to concave as the cirque glacier no longer received sufficient snowpack to sustain it.

Bill Prater, who named Ice Worm Glacier at end of glacier in 1986. He first visited the glacier in 1944, and it had changed little since then.

In 1991 evident that the glacier still reaches ridge on south side of glacier.

Ice Worm Glacier in 1996 extending to the ridge on south side, no lake at terminus

Ice Worm Glacier in 2001


Ice Worm Glacier, 2004. The lack of snowpack already is showing signs of the future for the glacier.


Ice Worm Glacier in 2005.


Ice Worm Glacier, 2015. The retreat led to the new the exposure of new small ponds in a sequence (paternoster).


The top of Ice Worm Glacier in 2018.


Iceworm Glacier in 2022. This collapse feature near the terminus shows the state of the glacier. A little of of snow remains from the winter, but blue ice near the top of the glacier in the background indicates the entire Ice Worm Glacier is retreating down the cirque.
The field painting on the right side of the notebook shows the Ice Worm Glacier for the first time as officially not a glacier. The debris covered ice, thinned profile, and lack of crevassing are clear. Art by Jill Pelto


Two data-sets for Ice Worm Glacier. The blue depicts the Annual Cumulative Balance, making it more clear a few “positive” years for the glacier. The green shows Annual Balance, highlighting the overall trend in mass loss.