Last of the Great Unknown
Synopsis: The story of Grand Canyon's hidden slot canyons, the canyoneers who systematically explored their drainages, and the secrets hidden deep within their walls.
Genre: Documentary
Cast: Todd Martin, Bill Formanek, Dave Nally
Director: Dan Ransom
Country: United States
Quality: HD
Duration: 22 min
Release: 04/26/2012
IMDb Rating: 8.0/10
