Andrew Peak Survey

Andrew Peak Survey

On the summit

April 27, 2024, 1am – 5pm

Results: Elevation 8,293.5 ft +/- 0.1ft (NGVD29 datum, same as quad uses)

There are still some remaining peaks in Washington that are within error bounds of inclusion in the WA Top 100 list and haven’t yet been surveyed accurately enough to know if they qualify. I’ve found surveyed points on the quad can be in error by up to 40ft in rare instances, so any peak within +/-40ft of number 100 on the WA top 100 list is an edge-case peak. (Currently Big Kangaroo is number 100 at 8,326ft). If I survey a peak with a differential GPS I can get errors down to 0.1ft, which will resolve any uncertainty about list inclusion.

My last survey was in early November, and since then enough snow has fallen that summits have been buried. To survey a peak without a permanent icecap it is necessary to survey the highest rock or dirt, not snow. So I over the winter it didn’t make sense to do any surveying.

The route

By now some summits have melted down to rock, so it again makes sense to conduct surveys. This weekend the weather looked driest east of the crest, and Andrew Peak was an edge-case peak in the dry area. I’d previously climbed Andrew in fall 2019 but hadn’t surveyed it. This time based on recent satellite images it looked like enough snow to bring skis. My cutoff in spring is I generally want at least half the trip mileage to be skiing to justify bringing skis. Otherwise I’ll bring snowshoes since they are a bit lighter.

This trip would be interesting since it would be the first time I’d combined surveying and skiing. It was the rare confluence of conditions where the summit had barely melted down to rock but there was still good snow coverage in the trees.

I drove up to the Andrews Creek trailhead Friday night and slept in the truck. Saturday I was moving by 1am. I carried boots and skis on my pack and hiked in waterproof hiking boots, since I knew it would likely be muddy. The snow started getting patchy around 7 miles in and was finally continuous around 9 miles in. This was farther in than I had hoped, so most of the trip was done carrying the skis. This made for a heavy pack carrying skis and survey gear.

Skiing up near Andrews Pass

The skies had started out clear but by sunrise the peaks started to get socked in the clouds. I expected precipitation starting around mid afternoon, but it appeared to be coming in early.

Before Andrews Pass I left the trail and crossed Andrews Creek on a good snow bridge. I then zig zagged up the south ridge of Andrew Peak until the slope steepened at 7500ft. There I booted up to the ridge crest and continued on to the summit.

Luckily the summit boulder was melted down as I’d hoped, with the highest rock point exposed. I’d brought a shovel and avy probe in case I needed to dig a cornice off the top, but that would be unnecessary. I quickly opend up the pelican case, set up the tripod and antenna on the summit, and started logging data. Just then the wind picked up and it started snowing. Visibility dropped to 50ft. The storm was indeed coming in early.

The dGPS on the summit

Sometimes I’ve noticed I get higher errors with the GPS when recording in a storm, and I hoped that wouldn’t be the case. I definitely wanted to take a full one hour measurement to get the errors down as low as possible. I brought a big down jacket and walked around taking pictures and eating snacks for an hour. It was unfortunately too cold and windy to lay down and take a nap.

Eventually my countdown ended and I logged the data and packed up. By then it was snowing pretty hard and I struggled to keep the GPS dry. (It is nominally waterproof, but I still try to be careful). I booted back along the ridge then put my skis on and had a fun ride down into the trees. I made it back down to Andrews Creek, then had to put the skins on. Unfortunately I think during that transition my crampons must have fallen off the back of my pack, because at the next tranistion back to boots they were gone! So if anyone finds a pair of petzl lynx technical crampons along the Andrews Creek trail they are probably mine.

Back to snow line

I skinned down the trail a few miles as the snow changed to rain, then found my stashed hiking boots in the trail. I didn’t expect any other people that day, so had just left them in the middle of the trail where I was certain to find them. I then hiked back the remaining miles on the muddy trail back to the truck by 5pm.

At home after 24 hours I post processed the results. I found Andrew Peak is 8,293.5 ft +/- 0.1ft (NGVD29 datum, same as quad uses). The quad-surveyed height was 8,301ft, so this means it is about 8ft shorter in reality. It’s definitely too short to be on the WA Top 100 list, though is still on the Top 200 list. I was pleased to see errors down to +/-0.1ft, which is about as good as I ever expect with a one hour measurement. Apparently the storm didn’t have too bad of an effect on the data.

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