Ausable Chasm is known as “The Grand Canyon of the Adirondacks.” It is a sandstone gorge that is about two miles long, carved by the Ausable River through the 500-million-year-old Cambrian Period Potsdam Sandstone around 10,000 years ago. The Ausable River runs through it and empties into Lake Champlain and is fed at the south end by the 91-foot-tall Rainbow Falls. Though not as grand as the Grand Canyon in Arizona, this chasm boasts of a continuous exposure of a section of