The Washburn fire, still burning in Yosemite National Park, is now 58 percent contained. And the iconic Mariposa grove—with its towering sequoia trees—has been spared. That’s due to ongoing firefighting efforts, but also to decades of work aimed at protecting the ancient trees. The architect of that program was Jan Van Wagtendonk. Van Wagtendonk was born in Palo Alto. He recently passed away, as the fire was still raging. He was 82 years old. Plant ecologist David Parsons was his friend and colleague and joins us to talk about his work.