Directed by Ken Burns, this 12-hour documentary series, which has won two Emmy Awards, looks at the development and history of America’s national parks.

Filmed over a period of more than six years in some of nature's most spectacular places from the Grand Canyon to the Everglades of Florida, the series is above all a story of people from every conceivable background, rich and poor, famous and unknown, who were willing to devote themselves to saving some precious portion of the land they loved.

The narrative traces the origins of the national park in the mid-1800s and follows its evolution for nearly 150 years, using archive photographs, first-person accounts of historical characters and personal memories.

The lengthy cast of characters profiled in the series includes James Mason Hutchings, one of the first people to promote Yosemite; John Muir, a religious mountain prophet who inspired generations of parks enthusiasts; George Masa, a Japanese immigrant whose photographs of the Great Smoky Mountains were instrumental in the battle to protect the region as a national park; and Stephen Mather, a wealthy businessman who used his personal fortune and genius to create a National Park Service.