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.
From Saddlebag LakeThe 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 trail begins just before the campground where this abandoned house is:
Walk down the trail that is just to the left of the dam. The trail stays to the left of the rocky moraine and descends quickly into the forest to join the trail that comes up from another campground and from Tioga Lake. Then see below the section " From Tioga Lake". Be aware that this is the least spectacular route to Mt Conness. You'll miss all the lakes.
From Tuolumne MeadowsThe 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.
From Tioga LakeThe 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.
One 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. Another trailhead is at the campground located just north of the junction with the road that goes north to Saddlebag Lake.
Both trails lead to Bennetville, and old mining town. The trail from Junction Campground is shorter and goes through the two remaining cabins. The trail from the north end of Tioga Lake is longer and goes through the mines, 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. Fantail Lake is where the trail ends, although you may still find cairns marking the easiest route. (On the way down note that most cairns will take you to the Carnegie Institute Experimental Station, too far to the east).
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.
In front of you there is a huge wall and you are entering the bowl of a glacier. The next lake is likely to be covered with snow: Alpine Lake. To reach the summit plateau, one has to find a way to climb the wall of the glacier. Go left (west) staying as close as possible to the wall. All of the chutes are likely to have some snow even in late summer. This is my favorite chute:
This takes you to a saddle. If you go left, you climb a confusingly named White Mountain (3675m), which is not the famous one down south in the White Mountain range. If you go right, you are ascending the plateau to Mt Conness.
(Click to enlarge)
Milestones from Tioga Lake:
Video from the top of Yosemite's White Mountain that shows the routes to Mt Conness
View from the top of Yosemite White Mountain that shows the routes to Mt Conness (video)
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.