The large island of the original lake – now just a hill amidst the surrounding cornfields – became a county park which has since 1973 been listed on the National Register of Historic Places. Archeological evidence suggests that early settler William Mason was not the first to appreciate the unique qualities of the original lake's island. Artifacts unearthed in a 1976 dig indicated evidence of habitation as early as 500 BC, thus making the location the oldest human habitation yet to be discovered in the state of Minnesota.