The trail is in a wilderness, and this marker is about 2000', as the crow flies, from the wilderness boundary.  I wish my picture would have turned out as sharp as yours.

Is this marker on a peak of a former lookout?

Yes I believe there was a LO located there at one time. It appears that the LO used to be outside of the wilderness area before it was a wilderness area. (How's that for an arcane clue?)

Would the wilderness area be the Roaring River Wilderness?

No not that one.  The location of this LO used to be just outside what used to be called a primitive area in the '30s. Now it is just inside the wilderness area.