Why is Mount Diablo so central to California's cultural and natural history? Find out on a hike near the 3,849-foot summit.

Presented by Save Mount Diablo, in partnership with Mount Diablo Interpretive Association. Originally published in 2019.

Featuring Heath Bartosh, Seth Adams, Robert Doyle, Lindsey Hendricks, Brian Peterson, Cyndy Shafer.

Photographs: Scott Hein, Stephen Joseph

and Seth Adams, Heath Bartosh, Steve Edwards, Brad Heckman, Helovi/istock, Joan Hamilton, Shawn Hanrahan/Texas A&M, Jepson Herbarium, Al Johnson, Neal Kramer/Strybing Arboretum, SWKrullImaging/iStock, Kit Leong/iStock, Marshman, Troy Montemayor, Carl Osborn, Bill Sattler, San Ramon Valley Fire Protection District, Arturo Reina Sanchez, Spyglass Hill, Terry Tomkins/USDA, Charles Webber/Cal Academy of Sciences, Westphalia/iStock

Music: Phil Heywood, Steve Arnold, Podington Bear

Illustration: Laura Cunningham, Bay Nature Magazine

Production, Narration: Joan Hamilton