I'll first apologize for the obscene lag time since we did this climb until posting this TR. We did the climb last fall and while I thought it was TR worthy I let the winter be an excuse for not posting it immediately. Recently goaded by Milan, who I met on Eolus, and a number of others interested in the Back Way up Wilson, I decided that this was worth doing for the community. The part of the climb that should be relevant is the last third, from upper Kilpacker basin to the summit and that is the part documented here. The standard route on El Diente will provide route information on the lower part of the hike and has not been included.
A couple of general comments. We were interested in this climb as an alternative to the standard exposed crux on Mt. Wilson's summit. Imagine our surprise when we found ourselves in exactly the same spot from the opposite side of the mountain! Time to backtrack, and that's part of what's fun about climbing.
This climb is about the same in terms of difficulty as El D, IMO. Some loose, some exposure, some slick dirt, but overall about the same amount of challenge. The trail is less beaten down and more care should be given because of that but it's the Wilsons and they're supposed to move around!
The only area that bothered me a little was the large talus and boulders just before you get into the upper couloirs. This route does not get enough traffic to settle and compact it. As a result, very large blocks move freely and that's just not a personal favorite of mine. The images were all taken on the way down in early afternoon and things may appear a little different in morning light. That sounds obvious, but has an impact in my mind.
One warning: I would not climb this route if there has been significant rain. The unstable nature of the rock and the dirt that holds it together would be much worse if the soils were wet. I'd stay away after heavy rain.
Thanks also to the other members on this climb who provided some of the pictures.
Mt. Wilson cannot be seen in the lower part of the basin as it is screened by the ridge from El D.
Wilson coming into view
As you climb higher it begins to rear above you but is foreshortened and not very impressive from a distance.
The summit appears
Start to aim for the left side of the drainage.
lingering snow fields in September
You will reach an area of large talus and boulders. Stay to the left and scout for a route through the initial steep terrain below the upper couloirs. There are several ways through this area. Take the path of least resistance.
The route into the couloir
The view from the area just above shows the couloir branching left with a large rock rib in the center.
View of the crossover from below
There are three options at this point. Left and up, takes you to the standard route crux. Right takes you to a class 4/low 5 headwall. The middle option, which takes you up and over the rock rib leads to easier ground above the headwall to the right.
Close-up of crossover
This view is up the steep, narrow couloir to the standard crux.
View up wrong couloir to standard crux
The terrain in this area is steep, but not a steep as the image conveys. This picture was taken while waiting for others to descend from above while in a safe niche.
steepness of terrain near crossover
The climb over the rock rib is not as hard as it looks but is easy to miss on the way up. There was no cairn. Pay attention to your right as you ascend.
climb up the rib
Once you've gained the top of the rock rib, this is the view up the gulley to the standard crux. It's not as steep as it looks.
view of upper couloir to standard crux
A view down from this area shows a steep drop to the left. Aim right on your descent. It is more obvious on the descent.
just above steep shelf, turn right
This shows the route from higher up and indicates where to start looking for the crossover. There are several ways across the rib, lower options were easier.
crossover from above
Here is a broader view, showing the relationship to El D and the connecting ridge.
view down couloir with El D and ridge
Another image from higher up the gulley nearing easier terrain around the summit.
Terrain just below the summit.
terrain near the summit
Looking down on a climber approaching the top.
climber approaching summit
Happy climbers on the summit!
A bonus view from the notch on the standard crux route.
An aerial view showing the route as a snow climb. I think this corresponds pretty closely with the TRs posted by Carl and Benners.