These giant trees stretch more than 300 feet above the ground, with hidden gardens and mysterious predators thriving within their canopy. Obsessive redwood climber Steve Sillett of Humboldt State University investigates their monster crowns, tallying biological material and discovering new record-breaking trees, while escaping falling branches and crashing trees in the process. Explorer-in-Residence Mike Fay charts the redwood range.

Title from container. Originally broadcast as an episode of the television series Explorer. Documentary. Also part of National Geographic's Ultimate nature collection. Bonus program: Wildlife wars USA: Elk harvest.