Rainier, Liberty Cap Spring Survey

Rainier and Liberty Cap Spring Survey

May 6, 2025, 12am – 6pm

Results: Columbia Crest has 0.5ft snow accumulation and Liberty Cap has 6.6ft snow accumulation since last Aug/September 2024.

This spring I’ve been taking elevation measurements on the five current and former icecap peaks of the contiguous US – East Fury, Colfax, Eldorado, Liberty Cap, and Rainier Columbia Crest. I want to measure how much snow accumulates over the winter to help understand why these peaks are generally shrinking. Based on nearby SNOTEL sites the max snow depth time of year is approximately late April through early May.

I surveyed East Fury April 18, Colfax April 24, and Eldorado April 27. The planned survey date for Liberty Cap and Rainier on May 4 had to be delayed due to high wind, but May 6 looked like optimal climbing and surveying conditions with low wind and warm temperatures. (Mt Rainier Recreational Forecast called for 11,000ft freezing level and 10mph summit winds, which is about as low wind as it ever gets up there). We got our official research permit approved from Rainier National Park, so were all set to take some measurements.

This time of year is the sweet spot for easy logistics at the park – gate closure restrictions have been lifted, but climbing permits are still self-issue at the Paradise old station. We planned to do a car-to-car trip to avoid carrying the extra weight of overnight gear up in addition to all the survey gear.

The survey plan was to take three dGPS units and tripods up. The first unit would be mounted on Columbia Crest with a 2.0m antenna rod and at least a 2-hour measurement. The big antenna rod would get the unit farther off the ground to help with multipath error, and the 2 hours should be sufficient time to get enough data to converge on the standard 0.1ft error. The second unit would be mounted on Liberty Cap at the same time to increase efficiency. The third unit would be a backup in case on of the others didn’t work.

Ideally the existing monuments around the mountain would also be surveyed to corroborate the results. The Summit 1 and Summit 2 monuments on the crater rim were stolen as of last summer, so those measurements wouldn’t be possible. The other three monuments are at Camp Muir, McClure Rock, and Paradise. This time of year the Paradise monument is buried under many feet of snow and very difficult to find, and the Muir monument is likely in a similar situation. But at least the McClure Rock monument is on a big boulder and likely melted out.

So we planned to take a measurement at McClure Rock afterwards to corroborate the summit data. Ideally it would be taken at the exact same time as the summit measurement, but a second-best option is to have it taken shortly after on the same day. We would be a group of four to carry all the survey equipment up, and would travel as two rope-teams of two to increase efficiency.

We carpooled down on the evening of May 5, getting to Paradise around 7:30pm. We filled out a self-issue permit at the Paradise Old Station, then parked in the overnight lot and took a nap for a few hours in the truck.

By midnight we were up and moving, with survey equipment equally distributed. Quite a few other teams were starting up at the same time, and it appears we weren’t the only ones that had noticed the excellent weather window. Conditions were icy and we made fast time skinning up to Pan Face, then cramponed up to a lower-angle slope. There we put on ski crampons and made fast progress to Camp Muir by 4am.

From there we switched to crampons and roped up for the icy glaciated terrain. We hiked over to Ingraham Flats as the sun rose, and views were excellent looking down at Little Tahoma in the alpenglow. We followed the established boot track and line of other skiers going up the Ingraham Direct. Up above it looked like a guided group had climbed up the Disappointment Cleaver and were above the cleaver by sunrise.

Crevasses were numerous and some thinly-bridged on the Ingraham Direct route, and I suspect that route might be out soon. We had to hop over one crevasse just below a steep snow climb up to Camp Comfort. There were buried pickets on the snow face, likely left by guided groups for running pro, though we felt comfortable enough not to clip them.

Above Camp Comfort the route got much easier, with no visible crevasses. We made efficient progress up, reaching Columbia Crest at 10am right on schedule. I quickly set up the DA2 unit on the big tripod on the highest point of the peak and started logging data. I then took Abney level measurements looking up to the SW Rim rock, which was melted out. I then walked over to the SW Rim rock, which is the highest point on Mt Rainier now, and took more angular measurements down to Columbia Crest. These could be used as corroborating measurements to for the GPS data. I know the SW Rim was 14,399.6ft last summer when I measured it, and I assume that shouldn’t change since it’s rock. So I can use the measured angles and some trigonometry to calculate the current elevation of Columbia Crest.

Conditions on the summit area were great with hardly any wind and warm temperatures. So the rest of the team decided to relax on Columbia Crest and guard the equipment while I went and measured Liberty Cap. I wanted to ski over, but the rime ice was not confidence-inspiring. So I packed up the other two dGPS units and set out in crampons. It was icy down to the Liberty Cap – Rainier col, then hard packed and wind scoured. I made it up to the top in about 40 minutes, then set up the 1.0ft mini tripod with the Promark 200 and Ashtech antenna. I logged data for one hour as I waited and admired the view.

I even had intermittent LTE coverage on my phone and was able to check some work emails. By 12:45pm I logged the data and headed back. One group was very carefully skiing down from Columbia Crest, and they said they were continuing over Liberty Cap and down Sunset Amphitheater.

I was back to Columbia Crest soon after, and quickly packed up the equipment. We walked our skis over the rocky crater rim, then started skiing down around 2pm. We crossed to the southeast edge of the rim, then followed our ascent route down. The slopes were a bit icy up high, but got gradually softer down to Camp Comfort. From there we put crampons on and downclimbed the steep face, since it was pretty exposed and full of crevasses for skiing. But after dropping a few hundred feet we got to mellower terrain and put the skis back on. We wove through crevasses skiing down to Ingraham Flats, then briefly took off skis to cross some rocks to the Cowlitz Glacier.

From there we skied back to Camp Muir and then down the Muir Snowfield. We reached McClure Rock at 4:30pm, and it was completely melted out. That was great news for surveying. I took out the big tripod and had it hug the boulder while I mounted the 1ft antenna rod on the monument on the top.

We hung out relaxing for an hour, then logged the data and packed up. It was more fun skiing back to Paradise, and we reached the parking lot at 6pm for an 18hr day.

I processed the data with OPUS and TrimbleRTX and found Columbia Crest is 0.5ft taller than I measured on Aug 28, and Liberty Cap is 6.6ft taller than I measured on Sept 21. These results suggest snow does not accumulate on Columbia Crest over the winter/spring and instead is mostly blown away. Columbia Crest likely maintains roughly constant elevation over the year except when summer temperatures rise above freezing and lead to melting. Degree days above freezing on summit have been increasing since early 2000s (see plot), consistent with shrinking late-summer elevation of Columbia Crest since early 2000s (see plot).

Final results for spring survey snow accumulations:

East Fury – 22.0ft (April 18)

Colfax – 17.3ft (April 24)

Eldorado – 25.3ft (April 27)

Liberty Cap – 6.6ft (May 6)

Rainier Columbia Crest – 0.5ft (May 6)

 

 

 

 

 

 

 

 

 

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