I want to share some photos and update this thread. Gabe and I walked around the EHC lake a month or two ago. He pointed out a spot on LIDAR that had potential as a charcoal mound. Today I was finally able to get over there and check it out, and it is indeed a charcoal mound. I took my 11 year old son with me and we were both really excited to find the location!
There are a few other locations nearby that also look like mounds. There is also an old trail that goes right by this location, but it doesn't appear to be part of the old indian cabin trail. Would Colliers or their helpers have cut their own paths through the woods? I'm also curious about the age of this mound. It is around one mile from Gloucester Furnace. The logical answer is that the charcoal was made for use in that furnace, but I'm not sure if there is a way to figure that out for certain