NEW WORLD ISSUES

Ken Burns was well along in making his much anticipated national parks documentary before he had the experience that for many crystallizes why the parks have such a hold on the American consciousness. He saw Yosemite for the first time.

"I've never in my life felt the way I felt at that moment," Burns says recalling his first look at Yosemite Valley. Weary from a promotional appearance in San Francisco, the East Coast native had driven to the California park to catch up with his camera crew there.

"It was like losing your virginity, or becoming a parent for the first time. You think you know what it's like to make love, or be a parent, and then you come to realize you really had no idea."

So it is no surprise that the legend of John Muir — the naturalist credited with preserving the now iconic landscape — and a Yosemite Park ranger play major roles in the 12-hour "The National Parks: America's Best Idea." Ranger Shelton Johnson, who is being hailed as the film's breakout star, pops off the screen the way historian Shelby Foote did in "The Civil War" and former ballplayer Buck O'Neil did in "Baseball."

But had it not been for Muir, who lived in Martinez, where his home is a national historic site, Yosemite and other natural treasures might now be gated communities or tacky theme parks.

"You could see Ken gravitating toward Muir the whole time we were making the film. He was captivated," said Dayton Duncan, a producer and lead writer on the project. "What Ken sees in Muir is what he sees in Louis Armstrong and Jackie Robinson — individuals with great enthusiasm for life and the ability to channel that enthusiasm in a way that has a profound impact on other people."