I think both Lyman. I'm thinking you have been around this block yourself. 

It would be the only easy way up or downstream on this side of the river.
I didn't post the flakes I found. Well just the large jasper one. Plenty flakes 
means sittin down for a spell. I also found fixed charcoal deep in the trail. 
Quartz, chalcedony, jasper, quartzite, gray and black chert and a tad of 
rhyolite from the fall line. The mountain is pure Sandstone, so all material was imported at least a  mile, up to 70.
The view of the wide river bottom land on the other side in a boreal landscape 
would have been spectacular and useful for hunting large animals.
Woodland buffalo, elk, deer and 300 pound beaver 

Zuma