Made before the lake,,, possible... The bottom is mostly rock there,, so I doubt there'd be any sustained skeg dragging there,,, the depth where the boat is usuallly runs 4-5 foot, but where the gouges are located the water is a little deeper.. Definatly very hard bottom though..
I am wondering if it's from logging before the lake was formed back in the teens..
There are some features like this at the other end of the lake between the main shore and an island,, so I am wondering about if this was done before the lake was formed by man..