This is supposed to one of the best if not the best hike in all the Canadian Rockies. Inafarawayland.com said it was number 2 and AllTrails folks think it might be the very best with 34 five star reviews.
It’s a tough hike. From the Lake O’Hara lodge, you start around the lake then immediately climb up to the Wiwaxy Gap. This is a super steep. It is a 520m climb (1800 feet) in just 1.9km (1.1 miles). That is some 26%! There are lots of switchbacks and quite a few ledges where you do not want to slip.
The Wiwaxy Gap itself is super windy given it is a ridge. Then you cross the Huber Ledges. To me this was the scariest 2km that you can be on. You follow the sedimentary layers and one slip and you are off the edge. So be careful.
At that point, you are at Lake Oesa and this is a fun place to have lunch.
It is then another 2km along the Yukness Ledges. It doesn’t feel nearly as scary, but there are definitely places where there can be snow as you work your way up the draws, so bring your micro spikes.
Finally, you then descend into the valley at at 8.8km (5.5 miles). At the valley floor you can bail out onto the East Opabin trail. This bailout should take you 4-5 hours.
Or if you have energy and the way is clear, you can continue on the All Saints Alpine Route that is the final ridge line hike. When you are finished, you will have hiked 10.6km (6.1 miles) and done 886m vertical (2700 feet) later.
Be prepared though. The weather can be very tricky. And stay safe!