Enchantment Peak Survey

Enchantment Peak Survey

June 26, 2023

16 miles

Summary – NE summit is true summit, 6-7ft taller than SW summit

Enchantment Peak is one of a handful of Washington hundred highest peaks in a very interesting situation – the peak has two summits of nearly equal height, with one much more difficult than the other, and they haven’t been surveyed carefully enough to know which one is tallest. Buckner and Cardinal used to be in this situation. But I brought my theodolite up those peaks to determine the true highpoint. On Buckner I measured the easier SW summit is 18 inches taller than the NE summit, and on Cardinal the more difficult south summit is 7 inches taller than the easier middle summit.

For Enchantment Peak climbers traditionally consider the NE summit the highpoint. This is a fun and short 3rd class scramble to a 6ftx6ft flat summit block. The SW summit is about 1500ft away and is reached by a very exposed 4th class scramble. Some climbers rate it low 5th class. The summit is a very narrow fin about a foot wide and 6ft long. As far as I’d researched it wasn’t definitive which peak was tallest, and thus which was the true summit.

Neither peak has a surveyed elevation on the quad, but the SW peak is enclosed in one additional contour. This means, based on the quad the SW peak is the highpoint. But the quads occasionally have contour line errors for points not directly surveyed. For instance, I used my theodolite to discover that East Fury, while only between the 8,280ft-8,320ft contours on the quad, is actually 8,356ft tall. It should really have one additional contour at its summit.

Lidar data exists for both of the summits of Enchantment. I analyzed the raw Lidar point cloud data and that showed the NE summit 3.8ft taller than the SW summit. That Lidar dataset has a published error of 4 inches, though that is under ideal conditions on flat terrain. Additional error can come from sampling frequency error. Elevations are measured at discrete points several feet apart. In the vicinity of the SW summit the points were up to 6ft apart. This means any terrain feature within those 6ft is not sampled.

The NE summit is a relatively large 6ftx6ft block that is mostly flat on top. As long as one point hit this block the elevation would be pretty accurate. However, the SW summit is a narrow fin 1.5ft wide by 5ft long (I have friends who had previously climbed it and showed me photos). It was possible that the Lidar points with 6ft spacing did not actually hit the summit, meaning the elevation of the SW summit was underestimated on Lidar. With this situation I would say Lidar data was not definitive in determining which peak was higher.

In theory a sight level measurement might be able to determine which peak is higher, though it would be tough with them so far apart. I couldn’t find any records of anyone doing a sight level measurement, though, even asking prominent peakbaggers who would probably know.

I concluded the only way to be certain which peak was the true highpoint would be to do a ground survey myself. Ideally I’d do the survey just like I’d done on Cardinal and Buckner – I’d mount the theodolite on one summit, set the scope perfectly horizontal, then have a partner stand on the opposite summit with a meter stick. I’d measure where the scope hit the meter stick, then we’d switch places and repeat.

This plan would be tricky for these peaks, though. Cardinal and Buckner had summits about 500ft apart, while Enchantment were around 1500ft apart. So it would be a bit harder to sight where the scope hit the meter stick. Also, the SW summit was very narrow and precarious, and probably too dangerous for a partner to stand on with the meter stick. It would certainly be too small to mount the theodolite on. Also, I didn’t have a partner lined up for the day I wanted to go.

My plan instead was to haul my mechanical theodolite up to the NE summit solo and take angular measurements. I had climbed it several times before and recalled it was just big and flat enough on top to mount the tripod and theodolite. I would then take measurements of the angular declination or inclination when pointing the scope at the SW summit. Then I could use the distance between the summits (calculated from Lidar to within a few feet) and trigonometry to calculate the relative height.

If possible I always like to get a second independent measurement to corroborate results. Since I couldn’t mount the theodolite on the SW summit I planned to mount it at an intermediate point. I would ideally mount it at a saddle or local maximum between the NE and SW summits. I would then measure angular inclinations to each peak. I could use my GPS combined with Lidar and the easily identifiable location of the measurement to calculate the distance between the theodolite and each peak. Then I could use the angles, distances, and trigonometry to find the relative heights between the peaks.

If this result matched my measurement from previous result looking from NE to SW, that would increase confidence in my results.

For timing, I wanted to do the trip on a weekday since the enchantments can get extremely crowded on summer weekends. I also needed visibility between peaks, so the weather had to be decent. Monday seemed to fit the bill, with only a small chance of afternoon thunderstorms but otherwise sunny.

I left Seattle early Monday morning and easily found a parking spot at the Stuart Lake trailhead. I was hiking up by 7:30am, along with a handful of other hikers. I made good time up to Colchuck Lake and stopped for a break at the classic picture location.

After the lake I didn’t encounter too many other hikers. I made it soon up to Asgard Pass, and stopped for another break as the clouds were starting to build. I didn’t like the trajectory of the weather.

I left the trail and hiked cross country beelining for the gully due south of the NE peak. But before I could get there it started hailing, raining, and thundering. Luckily I found an overhanging boulder to shelter under. I had a lot of experience finding shelter like this in the NWT where it rains off and on almost every day, and I’m always keeping in mind the closest shelter.

I ended up waiting under the overhanging for an hour until the hail and rain let up and the thunder ended. Once the sun poked out I cautiously continued up.

I think I stayed a bit too high since at one point I had to downclimb a 4^th class step and traverse a steep snow slope. But I eventually reached the melted out gully and scrambled up. I went straight for the NE summit, and by then the sun had dried out the south-facing rocks.

My pack was pretty heavy with all the survey equipment, about 50lbs. When I reached the base of the summit block I first ditched my pack and scrambled up to survey the scene. It indeed seemed big enough to mount the tripod, and safe enough to do the survey. So I descended, put the pack back on, then scrambled up.

The quarters were tight, with cliffs on all sides of the 6ftx6ft mostly flat pedestal of a summit. I very cautiously removed the tripod and extracted the big pelican case with the theodolite. I mounted the tripod, then mounted the theodolite.

I leveled the theodolite with the three bottom dials, then pointed the scope at the SW summit. I took measurements with the C and D dials, then rotated the base and took two more angular measurements. It was very tight up there standing on each side of the theodolite above a cliff, but I was careful and made it work. I also used my laser range finder to measure the height of the scope above the summit.

At one point a small cloud rolled over and dropped hail, but I waited it out and got all the measurements and plenty of pictures.

I then delicately packed up and downclimbed off the block. From there I hiked to an intermediate saddle between the two summits and dropped my pack. The weather was currently sunny and I had already gotten one measurement, so I decided to first scramble up and tag the SW summit before it started raining again. This wasn’t required for my measurements, but I wanted to tag it just in case it was the true highpoint.

I had read conflicting accounts of the difficulty between 4^th class and low 5^th. Ideally I would have brought my 30m rope and small rack to rope solo it, but that would have been way too heavy to add on to the survey gear. So instead I brought my rock shoes and planned to solo it if it was indeed 4^th class.

I scrambled over to the start of the exposed section, but the lichen hadn’t completely dried out yet from the rain. Some of the scramble required fractioning over slabs, and this didn’t really seem safe. So I decided to bail and maybe return after my measurements in the hopes that it had dried out.

I returned back to the saddle and mounted the theodolite again. I marked the location with my GPS, which I would later use in conjunction with Lidar and satellite images to calculate my distance to each summit.

I first took an angular measurement looking up at the SW summit, then another looking up to the NE summit. I intentionally took my time to give the sun a chance to dry the rock. I packed everything up, then returned with my rock shoes to the start of the SW summit route.

By now it had dried up enough that I was comfortable climbing it. I crossed briefly onto the NE side, traversed around a block, then scrambled back up to the ridge. From there I mantled onto an exposed slab, which was now dry, then friction climbed across to the base of the summit fin. From there I scrambled up to the fin and reached up and tagged the summit.

It was definitely too small to mount the tripod on, and about 1.5ftx5ft as I’d estimated. I quickly snapped a picture, then reversed my route and returned to my gear. Luckily it seemed the storms were finally done for the day. I made good time back down the access gully, then crossed snow slopes and regained Asgard Pass.

From there it was a smooth hike back down, and I reached the car a bit before sunset, then drove back late to Seattle that night.

At home I processed the measurements. My measurement from the NE looking to the SW summit had the SW summit 7.1ft shorter. My measurement from the saddle had the SW summit 6.2ft shorter. Rounding to the nearest foot, I thus found the SW summit is 6-7ft shorter than the NE summit.

This is consistent with Lidar results that the SW summit is shorter. So I am comfortable reporting this as my final result. It appears the quad has a contour line error and should have one additional contour line on the NE summit.

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