The site on Cracker Creek is purported to have been the Sumpter hyro plant, but I have not seen any details. The library has the entire Brooks Hawley photo colection and there may be a photo in there, but the collection is not yet available to the public.
The power to Granite came from Rock Creek untill the Plant shut down. You can still follow the clearing where the line crossed The Elkhorns. This line was a maintenance impossibility in winter, which was one of the reasons for abandoning operations. The last time I was there the old line shack at Ellertson Meadow was still intact, about 5 miles up Rock Creek from the power plant. There were a number of large mines in this area.