2025 Washington Icecap Surveys

In 2025, I worked alongside Eric Gilbertson to survey the historical icecap peaks of Washington State. The objective of the project was to collect co-registered ground-penetrating radar (GPR) and GNSS data to measure seasonal elevation changes, snow accumulation, and ice thickness. Historically, the contiguous United States had five permanent icecap peaks: Mount Rainier, Liberty Cap, Colfax Peak, Eldorado Peak, and East Fury.

My primary responsibility was field operations and GPR/GNSS data acquisition, while Eric managed survey-grade Trimble dGNSS receivers for elevation control. We utilized specialized equipment on loan from NSF EarthScope, including a Sensors & Software Noggin Ultra 100 GPR and a TopCon SGR-1 GNSS unit. To transport the equipment across glaciated terrain, I modified an orange ERA Group Pro Expedition Sled, cutting holes in the base to allow the GPR antennas to maintain a constant 1.34-inch height above the snow and ice for optimal data quality. The complete setup weighed approximately 65 pounds.

April 2025: Eldorado Peak Spring Survey

In April, we conducted a spring survey on Eldorado Peak to record seasonal snow accumulation. The previous year, it was observed that Eldorado's rock summit now completely melts out in late summer, meaning it no longer qualifies as a permanent icecap peak. We surveyed the remaining ice summit, measuring 25.3 feet of accumulated snow. As a practical workaround during this trip, we realized on the drive up that we had left some of our ski poles behind, so we stopped at a local grocery store in Darrington and used tiki torches as improvised ski poles for the descent.

May 4–5, 2025: Mount Rainier and Liberty Cap Spring Survey

Continuing our effort to record maximum seasonal snowpack, I joined the team for a spring survey of Mount Rainier and Liberty Cap. The data revealed a stark contrast between the two summits: Columbia Crest had only accumulated 0.5 feet of snow over the winter, indicating that high winds largely scour the summit, whereas Liberty Cap retained 6.6 feet of snow accumulation. This data was critical for understanding why Columbia Crest was shrinking at an accelerated rate.

August 21, 2025: Colfax Peak Survey Attempt

I led a three-person group with Olly and Matthew to attempt Colfax Peak. During this 17-hour car-to-car effort, we were unable to cross a large bergschrund blocking the final headwall and had to adjust our objective. Instead, we collected data from the low-angle glacier near the Colfax-Baker saddle.

This trip served as the primary field test for the sled design and sensor geometry. We encountered Noggin battery issues and GNSS connectivity problems—later traced to a defective cable, which we replaced for subsequent surveys. Despite the technical troubleshooting, we secured one high-quality, 300-foot co-registered transect.

August 24–25, 2025: Mount Rainier and Liberty Cap Surveys

We returned to Mount Rainier for a simultaneous static survey during a 29-hour continuous single-push climb. To ensure rigorous survey accuracy calibrated to the NAVD88 vertical datum, measurements had to be logged at the exact same time across the summit and at three established control monuments on the lower mountain.

This required a highly coordinated group effort. A lower-mountain team (Ethan, Darin, and Shannon) occupied the buried monuments at Paradise, McClure, and Muir. The summit rope team (Josh, Peter, Scott, and Anthony) helped distribute the heavy survey gear. I hauled the GPR pulk to the upper mountain to capture multiple sled-towed loop passes on Columbia Crest. Surface conditions dictated our data collection; while Columbia Crest offered a clean surface, Liberty Cap was covered in angled penitente fins, restricting our GPR acquisition to a single 15-foot flat lane where we could maintain proper surface coupling.

The survey data confirmed that Mount Rainier's Columbia Crest has melted down 21.8 feet since 1999, making the rocky southwest crater rim the mountain's new highest point. The GPR readings showed that the remaining ice on Columbia Crest is 16.5 feet thick, while Liberty Cap holds 34.8 feet of ice.

September 13, 2025: Eldorado Peak Fall Survey

To bookend the spring measurements, I led a four-person team (including Olly and Peter) on a 19-hour car-to-car return trip to Eldorado Peak. We captured the state of the icecap at the approximate point of maximum summer melt.

For this survey, I adjusted the sled geometry, moving the GNSS unit to a nose-mounted position. We towed the sled along the flat snow ridge crest for our first transect. For our second transect, we used two pickets to safely belay the GPR sled 100 feet down a consolidated 25° to 35° blue ice slope, capturing a uniform gradient profile of the underlying ice.

Final Thoughts

The 2025 surveys provided concrete, co-registered data on the state of Washington’s icecap peaks. Operating technical survey equipment in high-alpine environments required constant troubleshooting—from managing defective cables in the field to adjusting sled geometry for steep, belayed ice descents. Ultimately, the collected measurements and melt projections—which indicate that Columbia Crest may melt to rock by 2045 and Liberty Cap by 2047—serve as an objective baseline for future glaciological research in the Cascades.