Doesn't surprise me any. I live in an area that has been occcupied since the glaciers retreated. I live on the edge of what was once a huge glacial lake that is now only 90 acres in size. I hunt for stone points and tools every chance I get. This area is littered with them. Last year I found 3 flint drills in the same spot. I have many different ball knives, large and small, among all sorts of other tools. I also found a nice stone hoe and a large game ball last fall.
I have one area I search that produces paleo era items every couple of years. The paleo were more nomadic than the later people and no one has yet found a paleo encampment....just miscelaneous tools. I also have a few spots that were definately villages. You can stand in one spot and find broken pieces all over the place. Old burial mounds and occupied caves annd shelters are quite common around here. I know of two untouched mounds that I go to on ocassion....just to sit and reflect. No one knows, but me and the farmer. I will never tell either....if anyone finds out, they would be dug up and examined.
Just from what I have found, it is fairly obvious to me that man has been here quite a long time. The evidence seems to suggest that the ancient people, such as the glacial kames followed the retreating glaciers up into the Ohio valley.
Some people came across the land bridge, but in my humble opinion, man was here long before that.