6. Aug 2002. I received this picture and description from Troy.
I've attached what my opinion is about the route along the ledges and the trough. I just climbed it yesterday, so it's pretty clear what the route looks like. The only question in my mind is where the key hole really is. However what is clear to me is that once past the key hole the trail had a noticeable increase in altitude (right by a solid slab that goes to the base of the valley) and then drops down quite a ways (about 400-500 vertical feet) to the base of the trough.
I show the trail ascending where I think the solid slab goes to the base of the valley. If you look closely at your original picture you can see a noticeable line heading from the slab in the middle of the ledges to the trough, which I believe to be the trail. I also show in yellow a second possibility for the keyhole. In either case I believe the route I've outlined is pretty accurate. It's my best guess anyway. ;-)