Any place that was once covered by an inland ocean will be full of shark teeth. In southdakota farmers till up 100s of shark teeth in their fields.
...Used to look for sharks teeth in Florida. Hard to find on the beach, but up in the dunes, more plentiful. Lived on a Naval base and vehicles that made the ruts would turn up clean sand. It was a fun hobby, but, haven’t done any hunting for a long time. Still have a nice collection, the only thing I managed to hold on to all these years...
...South Dakota? What area???