I decided to create a route page for Peak C, because after working on the peak for several years, I was not consistently following the the social trail. Even after getting to know the area well, and then hiking at a fast clip, it takes at least three hours to reach the high basin. It's frustrating to be delayed by a faint trail and unnecessary detours when the objective is to reach a great climbing area early in the morning. My personal philosophy is to maximize time on the rocks above timberline, and so this section is intended to provide you with a clear and expedient trek up to the good stuff.
I'm a minimalist when it comes to the mountains - axe only, no GPS ever needed. So when I was finally able to follow the entire length of this trail, I only had my cell phone and a basic topo app to take a few waypoints. To the right of this paragraph are those coordinates, which I have overlaid onto some base imagery. Then by closely looking at the base imagery and the waypoints, I have been able to trace the entire trail. The description below should help you avoid delays and feel confident about reaching the high basin quickly.
From the Piney River
About 2.5 miles up-river from the vehicle trailhead, there is a large cairn that marks the start of the social trail. A brisk hiker will reach this cairn in just over an hour. You can find the cairn by paying close attention to the Piney River trail:
Cairn on the Piney River Trail
1.) About 2/3 up the main trail to the cairn, the trail has gained some good elevation above the river. Suddenly there are a few switchbacks where you will feel snarky about having to lose the elevation. Do this, and then the trail will make a few bends around some rock outcroppings. Beware of switchbacks where foot traffic didn't see the correct turn and created several false trails.
2.) The main trail will go right down to the river, and then braid out along some good picnic areas adjacent to the river bank. Stay away from the river bank and keep your eye on the main area of travel. If you do this, you will stay on the main trail and approach the base of a very large rock that is within shouting distance of the picnic area. The cairn is here, and it is marked on the imagery with the first waypoint. At the cairn, the social trail will briefly parallel the main trail, and then it bends left into a small gulley.
3.) Immediately, the social trail heads north and upward to clip off a lot of elevation. The social trail is generally clear for this first segment, except for a few instances where it crosses solid rock. Soon it reaches a high knoll with a great view. This is the second waypoint. A careful eye will see the trail trend to the left, gaining more elevation. You may start to lose the trail at this point. Keep looking left, and you will find that the trail goes through a thick muddy area filled with willows. After passing the wet area, bend right again and gain just a little more elevation. You come out above the willows and can look in an easterly direction toward the main creek which falls from the basin. This marks the third and fourth waypoints.
4.) This is where I think most people lose the trail. The large meadow here is lush and vegetation makes the trail faint or non-existent. Your instinct will be to head more north-by-northeast, and continue gaining elevation along the northwest side of the meadow. Do not do this. Bear more right into an east-by-northeast direction, hold your elevation steady, and traverse the meadow area. Aim for the mountainside on the eastern side of the valley, and enter the trees on the east side of the meadow.
5.) The trail becomes even harder to find inside the trees, but it is there. If you lose it, simply keep traversing northeasterly and toward the mountainside on your right. Waypoint 5 marks the location of the trail inside of this tree area.
6.) Soon, the sound of the creek will be on your right. Stay within earshot, and generally parallel the creek to gain elevation. The trail will climb steeply through several boulder areas, where easy scrambling is required. Some sharp turns in the trail are present where it turns to gain elevation through the rocks. Don't try to avoid the boulders: the easiest and most direct path is to stay on the trail and scramble through them. In the vicinity of the 6th waypoint, the trail will have gained elevation above the creek and the water will seem distant on your right. Keep parallel to the creek, and the trail will come closer to the sound of the water once again. Occasionally the trail will even out between the boulder areas and pass through the trees. By staying on the trail, you should be able to find a remarkably nice campsite near the creek. From the campsite, continue gaining elevation through one last boulder area. A final scramble brings you into the high basin.
Coming down from the moraines and the upper meadow
The trail is very obvious inside of the high basin. On your exit, and as you pass the final moraine, the trail will approach the first boulder area. Your instinct will be to head right and find a more gradual contour to lose elevation. You will lose the trail if you do this. Instead, stay left to follow the trail, although it will seem to disappear as it tries to go left of the first boulders. Steeply and suddenly, descend on the left side of the first boulder area. Keep the sound of the water close to your left. It's easy to lose the path of the trail on the first boulder descent, but as soon as you come out underneath the first boulder area, the trail is visible again. Continue downward through the mix of trail hiking and bouldering, now keeping the sound of the creek on your left.