Katsuk Peak Survey

Katsuk Peak Survey

Sept 30, 2023

Summary of Results: W. Peak 8678.2 ft +/-0.5 ft, E. Peak 8678.5 ft +/- 0.2ft. Too close to call which is true summit

Katsuk Peak (aka Mt Holyoke) is a Bulger Peak and Washington Top 100 peak located along Ragged Ridge in the north cascades. This is one of a handful of Top 100 peaks in the interesting situation that it has a double summit, with one summit more difficult than the other. I’m continuing my project of surveying to determine the most accurate list possible of the WA Top 100 peaks, which includes determining the true summit of double-summit peaks.

I’ve previously surveyed a few other peaks in this situation – Sherpa, Enchantment, Buckner, and Cardinal. Katsuk would likely be the trickiest, though. The normal route up Katsuk is a class 3/4 scramble up the south face of Ragged Ridge to the Katsuk-Mesahchie col, then it follows the east ridge to the east summit. There is also a western summit about 100ft farther along the ridge. To get there requires some exposed down climbing, then an exposed 4th class scramble. By eye the two summits appear to be very similar in height.

John Roper and Chris Roper made the first ascent of Katsuk/Mt Holyoke in 1968. They left the summit register on the East summit while waiting for clouds to clear then also tagged the west summit. Because the register is on the East summit, and this is the easier and closer summit via the normal route, this is in practice where many peakbaggers stop. It certainly looks official with an aluminum register with “John Roper 1968” carved on the outside. However, it has not yet been measured which of the two summits is higher and thus the true summit. The peak was not directly surveyed on the quad, the area is not covered by Lidar measurements, and I have not heard of any sight level measurements of the peak.

I got back from some international travels in early september and have been trying to squeeze in some last surveys before survey season ends when deep snow covers the summits. Colin had just climbed Katsuk and was curious to know exactly which peak was the highpoint. By late September the first snows of the season had dropped about a foot of snow on ragged ridge according to NOHRSC, but the weekend was forecast to be sunny friday through sunday according to weather.gov. The route faces south, so we expected most of the snow would have melted off by the weekend. Even if there were a foot of snow on the summits we could clear that off to take measurements.

The route would likely still have some snow, though, and that would make it sketchy enough we would want to bring a rope and maybe pitch out a few sections and rappel on the way down. Those conditions made me think twice about bringing my entire survey setup. The theodolite and tripod are at least 40 lbs total, while my differential GPS, antenna, mini tripod, case, and accessories are around 20 pounds. It seemed a bit risky hauling all that weight (60 lbs total) up exposed 4th class snow-covered climbing.

I knew the peaks were about 100ft apart, and at that distance my 1x and 5x 10-arcminute sight levels can theoretically resolve a 3.5 inch height difference. The differential GPS can usually get errors down to 1-2 inches with 30 minute measurements. So, unless the peaks were only a few inches difference in height (which seemed unlikely), those pieces of equipment would be sufficient. The weather.gov forecast for Saturday was sunny all day, with 0% chance of precipitation. So the GPS measurements should be very accurate. (My surveyor friends have told me unstable weather can increase the errors in measurements).

So I decided to leave the theodolite at home and go up a little lighter. Though, our packs would still be kind of big with the subset of survey gear and the climbing gear.

I had previously climbed Katsuk in July 2018, tagging all four ragged ridge peaks that day, and I had used the high traverse from Easy Pass. This weekend, though, NOHRSC was showing the whole ledge traverse might be under a few inches of snow. That could make it skethcy. Also, I recalled a few key areas near a waterfall where navigation was important. We wanted to do most of the approach in the dark to get more time for measurements on the summit and for pitching out tricky sections. Navigating the high traverse in the dark and snow sounded tricky.

Instead we decided to drop down to Fisher Creek and bushwhack up to gain the normal route. This would add extra miles and elevation gain to the day, but sounded like it had a higher chance of success. We planned our timing so we could start the bushwhack just by sunrise. Based on satellite images the bushwhack looked nice and open, perhaps avoiding slide alder.

We left the trailhead at 4am and made the quick hike up and over Easy Pass in the dark. We dropped down to Fisher Creek and by sunrise left the trail. Our route went through easy open grassy slopes and wove around a few slide alder patches. Eventually we cut through a small band of trees but then the terrain opened up and we hiked easily to a small tarn at 6700ft. There we took a break, and noticed the peaks above us on Ragged Ridge were all socked in the clouds. It appeared the sunny weather predicted for both Friday and Saturday might be incorrect.

We hiked up scree to a bivy site where snow cover started, then we headed up the ridge. Colin led the way since the route was fresh in his mind from an ascent two weeks earlier, while my memory was a bit rusty from five years ago. The snow cover increased as we entered the clouds, and it started lightly snowing. This would continue for the rest of the day. We referred to it as North Cascades sunshine that is white and accumulates on the ground.

Up higher the scrambling got icier and we made a few moves that we preferred not to downclimb on the descent. We planned to rap those. Eventually we reached the ridge crest and traversed left on the south side. One downclimb was a bit too sketchy in the ice and snow so we slung a horn and rapped it.

By 11:30am we made the final scramble up to the east summit. The clouds were thick but we could see just enough to make out the west summit. It looked about the same height, though both were covered in a foot of snow. I brushed off the snow from all the potential highpoint rocks on the east summit so I could get accurate sight level measurements. We decided to continue to the west summit for the first measurement. I usually like tagging the farther away and more difficult objective when peakbagging.

The downclimb to the notch looked sketchy and exposed in the snow, so we slung a horn and rapped down. I then scrambled around to the west side of the west summit and found an exposed 4th class route up it. It was on the edge of my sketch tolerance with the big pack but the holds were positive and decent so I soloed up it with Colin following.

I identified the highest point with my sight levels. It was the corner of a huge boulder that was obviously natural. I mounted the differential GPS and started logging data. Our grand plan was to continue after Katsuk to Mesahchie to get a height measurement there. Colin had not yet climbed that one. To make enough time we planned on 30 minute measurements on each of the three summits. Usually I would do a one-hour measurement, but that would be too long and likely have us navigating the complex terrain up there in the dark, which would be sketchy.

While the GPS was logging data I took sight level measurements to the East peak. It was almost exactly the same height within the resolution of the sight levels. I took pictures of the measurements to look at in greater detail at home. I also deposited a small summit register in a 1020 mini pelican case on the summit since there wasn’t one there yet. After the 30 minute timer ended I packed up the gear and Colin slung a horn on the summit for a rap anchor. It would have been way too sketchy to downclimb our ascent route.

We rapped down a cleft on the south side, then scrambled up the East peak by 1:30pm. Going up the snowy rocks was much easier than downclimbing would have been. I used might sight levels to find which rock was the highest on the East summit. All contenders were bedrock and not cairns. I mounted the GPS antenna on the summit and started taking measurements. The weather was still socked in and snowing, but we got occasional views down to the glaciers below on the north side. Mesahchie even popped out a few times, and it looked intimidating covered in snow.

Our speed had been slowed down considerably from the snow and we decided it was unlikely we’d be able to get up and down Mesahchie before sunset. So we decided to skip it and instead take a slightly longer measurement on the east summit of Katsuk. I took sight level measurements to the west summit, then after 45 minutes I saved the GPS data and packed up.

We scrambled down the ridge retracing our route. Visibility was still low but at least we could follow our ascent tracks in the snow. We were able to scramble the whole way back along the ridge without needing the rope. We then scrambled back down the south face. At one 4th class ledge we slung a horn and rapped down. By 4:30pm we reached the upper bivy site, then an hour later we made it back to the trail along Fisher Creek. We stopped to chat a bit with some other hikers, then got back to the trailhead by 9:00pm.

Colin continued east while I drove over to Cascade River Road for my next objective, surveying Mt Formidable the next day.

After processing the measurements at home I found higher errors in the GPS measurement than normal. The online tool OPUS gave me warnings saying ” The Quality Indicator for the network solution is less than 3.0. This is often a warning sign that the network solution was weak and tropospheric and ionospheric refraction in the project area were not strongly determined.” I think I just got unlucky with the weather. I got an error of +/-0.5ft for the west peak and I would expect much lower based on previous surveys.

From the GPS I measured that the height difference between the peaks was 3 inches but the errors were too high to definitively determine which is the highpoint. The error for the West peak was +/-6 in and the error for the east peak was +/-2 in. So, in one extreme case of the errors, the west could be 4in taller than east, but in another extreme the east could be 10 in taller than west. So the GPS measurements are unfortunately not definitive. The sight level measurements were at the edge of the resolution of the devices, which is 10 arcminutes. I would conclude from the sight levels that the height difference is around 3 in or less. But I wouldn’t be confident in which peak is higher when the measurements are at the edge of the resolution of the device.

So, in summary, the results are that the summits are likely within about 3 inches of height of each other, but it is inconclusive which is higher. To figure out the true highpoint I would like to return with my theodolite (20 arcsecond accuracy) and with the differential GPS on a clear sunny day. If I take 2 hour measurements on each summit that will theoretically get errors down below an inch. Those measurements should be sufficient to determine the true highpoint of Katsuk.

 

 

 

 

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