I've been interested in Mt. Thielsen for years, since I read about it in Oregon High and saw it from Crater Lake. It's a long drive from Seattle, though, so I never really focused on it much, until this fall, when we had to go to California for a wedding. Since I wasn't working, it made sense for me to drive down, and do a little peak bagging, and so Thielson it was.
I left Seattle around 8:30, and drove pretty quickly. Got to the trailhead about 4:00 PM. It isn't supposed to be that long a climb, so I figured as long as I was down off the steep part before nightfall, I'd be fine.
Jeff Thomas says that the summit scramble is 5.1, and I was worried about being able to descend that, so I brought my 30m rope, seat harness, and some webbing (and my headlamp, of course.) I'd communicated with a couple of folks on Cascadeclimbers.com about the route, and was informed that there were no rapel anchors up there, so I wanted to be prepared.
The trail is quite nice, soft and covered with fir needles, not at all the rocky trails of the north cascades. The hike in went pretty quickly, and I got to the Pacific Crest Trail in a bit over an hour. The PCT sure goes through some great scenery!
The trail follows a ridge, the west ridge of the mountain, I guess, and would be pretty easy to follow even without the boot track that takes you right up.

The sky was pretty clear when I started out, but the summit got socked in on the way up. Fortunately, by the time I got to the summit, it was clear again.


Looking for some drama, I tried to climb the steep ridge on the far left, where it drops off, and got about halfway up before I realized I was out of my comfort range for free-climbing. In fact, I got far enough up that I didn't feel comfortable down-climbing. (Checking back with Thomas, he calls this route 5.8, so it's not so surprising I was daunted.) My ego was mollified by seeing an ancient rusty, broken-off piton at this point. So I pulled out my rope, found a rock to sling, and wiggled into my seat harness -- and dropped my ATC! (fill in appropriate explatives here.)

Fortunately, I had some spare 'biners in my pack, and I managed to rig a caribiner brake from memory (and trial and error) and it worked fine to get me down, where I found my ATC sitting there patiently in the scree below.
So I crammed the rope and other gear back into my pack, and scrambled up the "normal" route with no problems, and got to the summit right around 7:00. It was certainly not as steep as Del Campo, which is rated at Class 3/4. Go figure.

Took some quick photos, signed the summit book (a deli recipt book in the beefiest summit register tube I've ever seen!) and headed down with all deliberate speed.

The hike out was no problem; the trail was easy to follow in the dark, especially since there were blue diamonds stapled into the trees pretty regularly. The mountain on the other side of Diamond Lake was illuminated by the twilight the whole hike out (the forests down here are much less dense than up north) and so there wasn't much fear of getting too lost. (Here's a tip, though; if you think you're likely to find yourself hiking alone in the dark in the woods with little animals scurrying around in the dark around you, you should probably avoid reading The Descent by Jeff Long. Just don't.)
Got back to the car by about 9:00, and headed down HW 230 to spend the night at Medford.