There seemed to be no mystery: The 7- by 10-foot pedestal on the coast probably collapsed on its own. Then a man named David Kalas said it wasn't time and weather that brought down the rock.

Its age was unknown. The pedestal, which was also known as “The Rock” and “The Duckbill,” was on the outer edge of the sandstone bluff on the Oregon Coast. The bluff, which is fenced off ...