Start at the Heart Lake Trailhead. The trail heads up a couple of switchbacks through an aspen forest before breaking out of the forest into an open brush covered slope. Soon you'll reach another switchback turn. This is where you depart from the Heart Lake Trail. You will head west on an unmarked trail into a small pine forest. The trail then turns north and heads up the southern slope of Sherwin Ridge. Gradually, the trail turns to a more northeasterly direction and heads up a very steep slope. Shortly, the trail flattens to a more gradual slope.
At this point the trail begins to disappear as you approach a pine forest. From here everything to the left (west) is what I call the west ridge. The west ridge is all lower elevation that the east ridge on up to Pyramid Peak. Most of the ridge on the west side is between 9,000 and 10,000 feet. The entire hike on the ridge is a cross country hike over small brush.
I’ve seen deer and bear up here. There are great views of the Mammoth Lakes Basin and Mammoth Crest to the south and the town of Mammoth Lakes to the north. At the western most end of the ridge only the canyon the Mammoth Creek runs through separates Sherwin Ridge from Mammoth Mountain. These are some of the best views of the eastern side of Mammoth Mountain.
Check out the Official Route.