Our family was camping at Big Whiteshell and took in this beautiful hike on the Big Whiteshell Hiking Trail. It is a 1.5km loop at should take people about one hour. There are a couple of points along the trail that offer splendid views. This is one of them, though it requires you to leave the trail for about 50m to get to it. (I would say it's the second best view along the trail, the best view was about 120m South, on the other end of the loop.
You are searching for a preform hanging in a tree. Enjoy the hike!