Lost Lake is a within walking distance of the center of Whistler. The trail from the town takes you along the river. Once you get to the lake you can take a walk around the perimeter. There is a beach area that is at one end of the lake that was a popular spot that day. (You can park there if you don’t feel like a walk from the town.) While the temperatures were not that high, a couple of people were even making use of the clear skies to do some sunbathing!
We too an alternate route around one side of the lake. A trail was named the Upper Panorama Trail so we took it. I think we were justified in assuming that this route would give us an elevated view of the lake. I’m not sure if there were spots that you could see the lake if you went off the trail but, from the trail itself, we were deep in the trees the entire time. There was no view of the lake from up there. It was a good walk though and an opportunity to walk off some of the bakery goods we had been sampling!