Mt. Thielsen (Oregon Cascades; 9,182')



Mount Thielsen looks extremely impressive from any direction, yet the summit pinnacle is only a very short fourth class scramble. On the summit one finds a lot of fulgurite, or fused rock due to lightning strikes. The mountain was named after a railroad engineer, Hans Thielsen. The summit pinnacle is not skiable, but the slopes starting 200 vertical feet lower provide a good ski descent, although they melt out fast in the spring.

Topo Map

Routes: West Ridge (I, 4th class, moderate ski descent)

Mt. Thielsen from the PCT in early October
References: Jeff Thomas, Oregon High Keep Climbing Press (Portland, OR 1991)
N.A. Dodge, A Climbing Guide to Oregon , Touchstone Press (Beaverton, OR 1975)


Date: October 8, 2006

Party: DB and John Toner

Route: W Ridge

Equipment: 50 m half rope

Time: Trailhead - Chicken Point: 2 hrs 25 mins
Trailhead - Summit: 2 hr 50 mins
Summit - Trailhead: 4 hrs
Roundtrip from Trailhead: 8 hrs 30 mins

Comments: Time down includes 90 minutes looking for a missing camera

Trip report:

John was looking for a belay on the summit pinnacle, and I did not mind another trip in perfect fall weather, so we agreed to meet on Sunday around noon near the summit of Thielsen. I left the trailhead at 9:30 and met John shortly before noon at Chicken Point. I set up a toprope, and soon we both were having lunch on the summit. The weather was very nice, with a few puffy clouds forming, and some more substantial cloudiness towards the north.

We descended the scree and continued on to John's camp just below the PCT. Just as I was about to leave (John wanted to spend a second night) I missed my camera. Remembering that I had left it at Tenaya Lake in August after swimming, I was convinced I had done the same thing and left it at the first big tree on the scree slopes, where I had emptied my sneakers and drunk some water. So I went back up. I got to the tree, no camera. I continued up the scree slopes until I could no longer be sure where exactly we had come down, no camera. Frustrated, I went back down, and emptied my pack, without any real hope. Sure enough, there it was, in the main compartment, where I NEVER put it! I still have no good idea how it got there. But anyway, I was relieved, took leave from John and ran down to the trailhead.

Nice trip, although I turned the 3,800-foot climb into a 5,000-foot climb. Next time I'll empty my pack first, before going halfway back up the mountain.

Photo Gallery:

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John just below the summit.

John on the summit.

Dietrich on the summit

Dietrich in the saddle.

John descending the scree slopes.

View of Mt. Bailey from treeline.


Date: March 25, 2005

Party: Paul and Dietrich Belitz

Route: W Ridge

Equipment: AT Skis

Time: Trailhead - Saddle at ~9,000' : 6 hrs
Saddle - Trailhead : 1 hr 25 mins
Roundtrip from Trailhead : 7 hrs 35 mins

Comments: Time up includes lengthy lunch break watching the weather

Trip report:

2005 had by far the worst spring break weather we had ever experienced. This was all the more frustrating as the entire winter had been anomalously warm, dry, and sunny. The snow pack was accordingly abysmal, and originally our idea had been to go south to Mt. Shasta in order to get some skiing in. When the weather was horrible day after day, we abandoned this idea and focused on a day trip on Friday, when a break in between two storms was supposed to produce weather that would suck less.

Two years ago we had attempted Mt. Thielsen on skis, only to get whited out high on the west slopes. Thielsen's pumice slopes are rather smooth in places, which is good if the snow pack is low, and so we decided to try again. We figured that the summit pinnacle would be all plastered with rime ice (which turned out to be correct), and that summiting was not an option in the context of a day trip, so we took skis only and set our sights on the saddle at almost 9,000' where the scramble up to Chicken Point starts. The driving was slow, and we started out from the trail head only at 9:30, despite having left home at 6:30. Diamond Lake greeted us with the usual view: A low cloud ceiling, and no mountains whatsoever in sight.

There was barely enough snow for skinning off of the snow park, but the snow was nice, fresh powder. We skinned up to the PCT in a bit over two hours, following the summer trail for about half of the way, and took a break. As we continued up the west ridge we occasionally caught a glimpse of the summit pinnacle, but then the weather deteriorated and we figured that soon we would get whited out, just like two years ago. Sure enough, once we reached the bottom of the cliff that splits the west slopes the clouds caught up with us. We stopped for a lunch break, brewed up, and contemplated the weather. While we were eating, visibility improved, and we could see the saddle that was our objective not so high above us. It was 2pm by then, but we figured we could reach the saddle within an hour, and after some more deliberation we kept going. We actually managed to skin all the way into the saddle, although the last 200 or so vertical feet were a bit marginal, with lots of rime ice and lots of rocks sticking out. Strangely, here at almost 9,000' there was much less of a base than around 7,000'; it was essentially the new powder on bare rocks. We reached the saddle at 3:30pm, our turnaround time. I am still suprised that it took us six hours to climb 3,700', but skinning is slow, and Paul was breaking trail almost all of the way since my BCA skins were balling up and gave me lots of trouble. I'll have to find myself some better skins.

We admired the views and the rime ice-covered summit for a few minutes, then we figured it was time to get down. The top section did not have enough snow cover for skiing, so we downclimbed until we were past the rocky section. Then we put our skis on and experienced some of the best powder we've ever found in Oregon. The skiing was unbelievably cool! With the snow pack as poor as it was, we made sure to reunite with our skin tracks at the PCT for the trip through the woods. To our surprise, the tree skiing was also very good, and we managed to ski all the way to the sno park without even scratching out skis, although we were on about an inch of snow at the end. Even though we stopped often to take photos, the skiing was so fast that we got to our car with 90 minutes of daylight to spare.

It was a very nice trip by any standards, but by the standards of this horrible spring break it was superlative.

Photo Gallery:

Click the pictures to see a higher resolution image, or watch the slide show (caution: 10.7 MB).

There wasn't much snow near Diamond Lake. As we climbed up to the ridge the weather first improved, and then deteriorated, but occasionally we could see the summit pinnacle. Around 8,200' we got whited out, so we had lunch and waited for the clouds to pass.






We resumed climbing and could soon see Crater Lake as we approached the rime ice-covered rim and tuff formations. The saddle was plainly visible now. Getting there was a pain, but we made it just by our turnaround time.






We had to downclimb the first 200' due to poor snow cover, but below the rock bands we started skiing in perfect powder with the summit pinnacle as a backdrop. Going down was very fast and we got back to our car with plenty of daylight to spare.


Date: October 2, 2004

Party: Dietrich and Monique Belitz

Route: W Ridge

Equipment: 9mm half rope, some slings

Time: Trailhead - Base of Pinnacle : 3 hrs 45 mins
Trailhead - Summit : 4 hrs 10 mins
Base of Pinnacle - Trailhead : 2 hrs 15 mins
Roundtrip from Trailhead : 7 hrs 30 mins

Trip report:

Having been frustrated in Spring twice, we decided to do Thielsen in the Fall, as Monique had never summited it. We got a leisurely start at 9:30 from the trailhead, and hiked up to the PCT in a bit under two hours. On the way up the West Ridge we caught up with a large party, and in the notch below the summit pinnacle commonly known as Chicken Point it was quite busy. We should have gotten an earlier start after all! Monique was not comfortable soloing the pinnacle, so I got the rope out and gave her a belay from above. There was more rubble on the ledges than I remembered, and the rope promptly dislodged a rather large piece, despite Monique's efforts to flip the rope over it. Fortunately, it did not hit anybody. The summit was somewhat crowded, and so was the descent, with a fixed rope, our rope, and a few soloists all intermingling. After lunch at Chicken Point we plunge-stepped down the scree slopes to the PCT, and then followed the trail back to our car. Except for the many parties on the summit it was a very nice trip in perfect fall weather.

Photo Gallery:

Click the pictures to see a higher resolution image.

Mt. Thielsen from low on the trail. Monique at the PCT intersection. Monique approaching the summit pinnacle. Diamond Lake and Mt. Bailey in the background. Monique on the summit, looking east. Tuff formations just below the summit. DB and MB at the PCT intersection.


Date: June 6, 2004

Party: Dietrich and Monique Belitz

Route: W Ridge to ~8,000'

Equipment: AT Skis (DB)

Time: 6 hrs roundtrip Trailhead - High Point

Comments: Time includes laps on the N slopes of the ridge

Trip report:

Some day I'm going to summit Thielsen in Spring and ski from the base of the summit pinnacle, but today again was not that day. I had been sick on Memorial Day weekend and was eager to get out, and I wanted to do some skiing before the season is over, so we decided against Smith Rock and in favor of the mountains, despite a lousy weather forecast. We figured we'd go over Willamette Pass and then decide whether to go north to South Sister or south to Thielsen.

It was raining all the way up Willamette Pass, and Diamond Peak was solidely socked in. On the east side it looked better, though, and Odell Butte was clear, so we figured the thing to do was go as far east as possible. Thielsen is not any farther east than Diamond Pk, so we turned north on Cascade Lakes Highway, thinking we could always do Bachelor if things did not look good enough for South Sister. Thirty miles up Cascade Lakes Highway it started to rain again. It was still raining at Devils Lake, and the obsidian cliffs were just barely visible. We continued to Bachelor, where it was raining even harder, and the wind was blowing like crazy, with gusts that rocked the car. After sitting there for a while we decided to bite the bullet and go back south after all. On the highway we picked up two dudes who had attempted South Sister, called it quits at 8,000' and taken the wrong gully back down. They looked extremely wet and appreciated the ride back to their car. Two and a half hours after we had left Highway 58 we were on it again, this time heading south. On 138 it started to rain again, but at Diamond Lake it was dry. No sign of any mountains anywhere, though. By now it was past 11am. We looked at the watch, at where Thielsen should have been, at each other, and quietly left all technical equipment in the trunk, as summiting was not realistic under the circumstances.

After half an hour on the trail we hit snow, and after two hours we reached the West Ridge above the PCT. The cloud ceiling had risen a bit, and occasionally we even got a glimpse of the summit pinnacle. Pretty soon the ceiling settled at around 8,000' though, and remained stable there for the rest of the day. We went up the ridge for a while, then Monique took a break while I did some laps down the north slopes of the ridge. The skiing was good, with a somewhat wet layer on top of well consolidated stuff. After having done around 1,200' worth of extra credit this way we kept going up until we hit the cloud ceiling. The views were breathtaking. Amazing colors on Diamond Lake, the slopes of thielsen and Crater Lake Rim drifting in and out of the clouds, and extremely dark clouds engulfing us at times. For some stupid reason I did not take a camera, which was too bad.

Going down consisted of nice skiing down into the trees, followed by 1,000 vertical feet of survival skiing, followed by tree hopping until we intersected the trail. On the drive back we still could see the ceiling on Thielsen, in exactly the same location as when we had been up there.

Despite the awkward start it was a very nice trip. Some day I'm going to summit Thielsen in Spring, though!


Date: May 25, 2003

Party: Dietrich and Paul Belitz

Route: W Ridge to ~8,800'

Equipment: AT Skis

Time: Trailhead - High Point 4.5 hrs, High Point - Trailhead 3 hrs, roundtrip 7.5 hrs

Comments: Deep, wet snow

Trip report:

We were desperate to try out our new Mira skis, and settled on Thielsen to do so. We started out in very nice weather, hiked up to the PCT intersection, and then skinned up the West Ridge. Once on the ridge the weather started to move in, and at around 8,600' we got whited out. The terrain was quite steep by now, and we boot packed again, postholing in deep, unconsolidated snow. The weather was clearly deteriorating, and at around 8,800' we called it quits. Being unfamiliar with the skis, and unable to see anything, we did kickturns for a while, but from around 8,300' on we were able to link turns in the heavy snow. The cloud ceiling had dropped all the way to tree line by then, but by the time we got back to the car the weak front had moved through, and the summits were visible again. We had perfectly timed the three or four hours of bad weather! Oh well, so I'll have to come back and summit under spring conditions (I've done it many times in summer or fall).