Last of the Great Unknown
8.0/ 10 1 votes 2012-04-26 0h 22m 0 popularity
The story of Grand Canyon's hidden slot canyons, the canyoneers who systematically explored their drainages, and the secrets hidden deep within their walls.
Director: Dan Ransom
Bill Formanek
Self
Todd Martin
Self
Dave Nally
Self
Rich Rudow
Self
Guy Smith
Self
