April 21 marks the birthday of a guywho’sarguably the nation’s most famous tree hugger.

John Muir was a sheepherder, storyteller, fruit rancher,citizenscientist, tinkerer, philosopher, conservationist, and first-class wanderer.

He first saw what later became Yosemite National Park at age 29 or 30 in 1868 and, since then, the two have been inseparable. Muir fought for, and secured, Yosemite’s protection and agitated for the protection of other lands now part of the national park system.

The pa...