Tresidder (with the emphasis on the second syllable, as tetchy Tresidders will tell you) is a peak southwest of the Cathedral range in eastern Yosemite. Its summit is a long ridge with a point at either end, the southern one supposedly slightly higher than the northern one. Columbia Finger is a neat-looking point south of Tresidder, with an easy ramp on the north, steep faces elsewhere, and an overhanging summit block.
After Lyell, the short, efficient, scenic approach was a welcome change. Though the trail is yet another horse-ruined highway, it is only a few miles long, with constant views of Tuolomne’s domes and the impressive Catheral range — Cathedral and Eichorn, Echo Peaks, and Matthes Crest. Tresidder itself, an uninspiring thing from the west, looks all right from the northeast. The northern point also looks higher from there, and the nice slabs leading up to it from upper Cathedral Lake make it more tempting than the south point.
It is a short class 3/4 climb from the slabs to the north end of the ridge, which is quite narrow and has no obvious place for a summit register. From the top, the south point looks like it might be slightly higher, and the ridge-top is seriously intimidating, so we traversed around on the sand to the west and came at the southern summit from the south and southwest.
Both points are supposedly 4th class, but the contortions I went through to reach the south summit felt distinctly harder — probably as hard as anything I did on Conness earlier. I finally found a way up a couple of chimneys, and while there was no register, there was at least a giant rappel sling to show that humans had been there. Getting down was a bit of an ordeal, with some careful stemming to retrace my steps.
Columbia Finger is an easy jaunt to the south, with a short class 3-4 climb and a bit of an exposed walk along the summit block, which sticks precariously over the east edge. There is a great victory shot looking north toward Cathedral from the ledge south of the summit. From there it was easy slabs down to the JMT, which, like any good road, has had some lanes added along this popular stretch.