Thanks you all for the nice comments.
Davin: Opabin Plateau and the area around MacArthur Lake teem with larch trees. You will have a blast if weather cooperates. Yes, we returned to Le Relais Shelter shortly before 6pm to catch the 6:30pm bus.
ian779: Right, I was lucky to have clear blue skies with no haze in the area. It's usually other way around.
pmjwright: BC board is all about Vancouver based hikes (90% of it anyway). I often miss great TRs from the BC side of the Rockies just because they have been posted on a board that has little to do with the Rockies. I assume many people do the same. On the contrary, anyone interested in the Rockies checks Alberta board. Therefore, posting Lake O'Hara TR on Alberta board seems to me a very logical decision. We have been discussing this topic a lot on this forum in the past.