Last of the Great Unknown
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.
- Είδος: Ντοκυμαντέρ
- Διευθυντής: Dan Ransom
- Ηθοποιοί: Bill Formanek, Todd Martin, Dave Nally, Rich Rudow, Guy Smith
- Χώρα: United States