Climbing Redwood Giants tells the story of a man obsessed with monster redwoods. To say that Humboldt State University’s Steve Sillett likes redwoods is like saying Edmund Hillary was keen on mountains or Jacques Cousteau had a fondness for the sea. Just when Steve Sillett thinks he’s climbed and measured the tallest living tree on earth, another one turns up in a hidden valley of California and breaks the record. Sillett, the first researcher to explore the redwood canopy, awaits the analysis of a new aerial survey that may point to the next record-breaker. As Sillett studies redwoods limb by limb, explorer Mike Fay is charting the entire redwood range step by step to get a sense of the past and future of the world’s tallest living trees.