Last of the Great Unknown
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
Director: Dan Ransom
Cast: Bill Formanek, Todd Martin, Dave Nally, Rich Rudow
Country: United States
Quality: HD
Runtime: 22 min.
Release: 2012
IMDb: 8/10
