I didn’t go on the reservation.all my fossils from webster.all my fossils were collected on the side of the road next to lakes were we fished.they would put boulders on the side of the road for erosion control.thosefossils look a lot older than recent times.is there a chance that the glacial activity brought much older rocks down into s.d.?because there used to be a shallow sea there.the Tetris sea.which is much much older than 65 million years.ive even found ammonites and trilobites in that area.