This hike is actually park of a multi-day backpacking adventure but you can hike just to the viewpoint which is what we did and it turned out to be our favourite hike in all of Yukon!
The hike to the viewpoint is 6KM round trip. Although not far, the terrain makes this a tough and long hike. It took us 6 hours to complete this with an hour of that being stopping for lunch.
The terrain is lose rock and a lot of elevation gain.
Lookout is called Mount Monolith & you will see it on the map at the start of the trail. There is no sign for the lookout on the trail so you really just stop wherever you feel like you have seen your favourite view.
AllTrails Link: https://www.alltrails.com/trail/canada/yukon/grizzly-lake-campsite