Director Ken Burns said while making his six-part documentary about the country's national parks, he became enamored with the writings of Muir, who is credited as a pioneer in the preservation of the U.S. wilderness, the Bay Area News Group said Saturday.
"It's such a great thing to be hit over the head when you're working on a film," Burns said. "I just wasn't prepared for what a great writer he (Muir) was. Mark Twain said the difference between the right word and the almost right word is the difference between lightning and a lightning bug. John Muir was lightning."
Yosemite National Park ranger Shelton Johnson, who appears in the 12-hour documentary, said national parks are national treasures every U.S. resident should embrace.
"I think every citizen has a responsibility to visit the national parks," Johnson said. "These landscapes helped to shape us as Americans."
The Bay Area News Group said "National Parks" debuts on PBS on Sunday.