Mt Conness (3837m) is one of the highest mountains in Yosemite, third to
Mt Lyell and Mt Dana.
There are at least three ways to reach the summit of Mt Conness, on the far eastern border of Yosemite Park. The most popular and shorter is from the dam below Saddlebag Lake to the Carnegie Institute Experimental Station (just a shack in the forest) to the northern side of Alpine Lake up northwest to the eastern ridge and then following the ridge westwards to the summit plateau.
The most spectacular route is from the Young Lakes (usually reached from the Lembert Dome parking lot at Tuolumne Meadows): after the second Young Lake, walk down into the valley below heading northeast, ascend the canyon upstream to the right of the massive mountain that now covers Mt Conness and at the plateau lake (3200m) look for a use trail on your left (south side of that mountain) that leads north up to the summit plateau. Head north for the colossal summit block and climb the rocks (only class 2, but a couple of places have a lot of exposure). Note that the USGS marker is *not* at the top: it is at the base of the summit block, where two low concrete pillars have been built. At the top there is the summit register, but i could find no USGS marker.
The third route (described below) is also spectacular and a bit shorter. This is mostly a cross-country hike from Tioga Lake to Mt Conness via a number of lakes.
The trailhead is on the northern side of Tioga Lake, which is located a few minutes east of Tioga Pass (the toll entrance station) at an altitude of about 3,000m.
The trail leads to Bennetville (and old mining town, but there is only one mine with some equipment left). After two unnamed lakes (Bennetville 1 and 2), one reaches Shell Lake. At the fourth lake there is a sign announcing the beginning of the Hall Research Area. The next lake is Fantail Lake. You proceed up the obvious gulch in a general northwestern direction. If you left early in the morning, you are basically following your shadow. Fantail Lake is where the trail ends.
After Fantail Lake, you are better off trying to maintain altitude, as the contour would send you down to the Finger Treble Lake (three lakes separated by thin strips of land). If you pay attention, you can see Saddlebag Lake way to the right (dam and road). Past these three lakes (if you maintained elevation), you will see a valley with a meadow on your right. Then the gulch start going seriously uphill. There is vegetation even at high altitude here, so you may have to do a bit of bushwhacking.
Needless to say, there is a lot of water around: creeks, little waterfalls, etc. You really don't need to carry any water at all until the very top.
The next lake is likely to be covered with snow: Alpine Lake. To reach the summit plateau, one has to traverse and climb west.
(Click to enlarge)
Milestones from Tioga Lake:
From the Young LakesFrom Tuolumne Meadows follow the Lembert Dome trail past the Dog Lake trail junction. It is about 10 kms to the first Young Lake. Then follow the use trail that goes east and cairns will lead you to the summit plateau.
CampingYour best bet is the campground near Mono Lake or camp anywhere in the National Forest east of Tioga Pass.