There is no doubt that this entire area has had people living in it for a very long time.
I dropped into the creek that point came out of the day before deer season, and I worked my way up the creek, looking for large pieces of workable stone. I was picking up the likely looking pieces and knocking a couple of flakes off to see what it was.
It rapidly became clear, that most such pieces had already been picked up and had had a couple of flakes knocked off to see what they were. Some of the scars were old enough to be forming patina over the scars again. Some were old enough that the patina on the scars appeared the same as the other cortex.
I believe I have found the material they were looking for, but it will have to wait until I get time to go again, since I figured the hunters would not react well to someone playing in the creek, and hitting rocks together!
The area you mention is just about the same distance from the river as the area I found mine in is, and pretty much every such large drainage here has had people living in it for a very long time!