High points of land near water have always been good spots for paleo artifacts.
Assuming the same water was still there it would have served as a vantage point to spot game for a long distance coming into the open to drink and eat the greens along the river.
It would have been the perfect spot to recon.,gear up,knapp,camp..ect.
Those places also erode quickly.
Also..some places that are water now may have been low grass land then...it pays to research the area.
A high vantage point would allow them to track herd movement.
Personally .. I would stick to areas of the river bank that collect material and rock bars.
Water movement and gravity has been working that area for a very long time.. the numbers are bound to be higher there and statisticaly you should have a better chance.
There are some very old rivers in Florida that have areas with a rock bottom that has not changed all that much in a very long time..these areas are shallow compared to the water on either side... large numbers of paleo artifacts have been recovered in these places.
Its believed they were used by wild game as an area to cross the river and that was taken advantage of by the Natives.
They would ambush the game once in the water probably from both sides...and basically unload on them.
These places are called "kill sites".
You might want to research that term ever being used to describe a section of river near you.