I once tried to do that loop as an overnighter, but got scared away when the sky above the slot in Bull Valley looked gray. We saw when we got out that it was just a wispy cloud, and it never rained, so we did an afternoon hike into Willis to salvage the day. This photo really reproduces the colors there well.
Thanks! I love that hike from Bull Valley Gorge to Sheep Creek and out Willis Creek. It takes about 10 hours - taking your time, so it could be done in one day with time to spare, but it would be a fun over nighter too. :)
Hopefully you will get another chance to do it.