Legendary film maker Ken Burns has brought the greatest American stories to life on public broadcasting stations for more than 25 years. This fall, he shares the story of the national parks.

Burns' films are often historical narratives, but when we caught up with him last week in Staunton, he gave a grim warning about the future of the Shenandoah National Park and others like it.

"Where else in the United States can you be two hours away from Washington D.C. and yet be in the middle of nowhere and hearing almost nothing but a babbling brook and the songbirds," asks Karen Beck-Herzog, Shenandoah National Park spokeswoman.

The park is nature in its purest form.

"Shenandoah is a smaller park. It's intimate," says Burns. "You're basically going along the spine of Skyline Drive. I like that intimacy."

Documentarian Burns tells America's greatest stories from baseball to the Civil War and now, the national parks. It's a story that, for Burns, began in Virginia years ago.

"My dad took me to Shenandoah National Park, the first park I ever went to when I was six years old in 1959. I will remember that day until I die," says Burns. "[My dad is] no longer here, but I can still remember what his hand in mine going down those trails."

Shenandoah's rolling peaks left an impression on the film maker. Fifty years later, Burns and co-producer Dayton Duncan have filmed in all 58 national parks to trace the birth of the park system.

The story of Shenandoah National Park is one of conflict that is still rooted deep in western Virginia almost 75 years later.

When the park was authorized in the 1920s, thousands of Virginians were still living on the mountains. Some gladly took payments for their land, others were forcibly removed through a condemnation act.

"They definitely felt that connection was broken and it created a very, very deep conflict between some people and this park," says Beck-Herzog.

In 2009, those feelings of resentment linger. Protecting the parks into the future will be the responsibility of Shenandoah's neighbors.

"There's no way we can protect this park on our own and it gets back to that connection," says Beck-Herzog.

Threats are ever present in Shenandoah. Poor air quality can make for hazy days, blocking the expansive vistas. Development below is a creeping reminder of the destruction of mankind. Exotic plants and animals threaten the purity of the park. However, Burns says complacency is the greatest threat.

"All that's required of us is that we visit this property once in a while and check it out. It is ours, and that we pass it on to our children, that we put it in our will. If we don't do that, then as so many things, they collect dust, they don't get enough maintenance and they decay and that's what we can't have happen," says Burns.

Burns calls the national parks America's "best idea," the Declaration of Independence applied to the landscape.

"The parks humble you in the best sort of way. It's better than church. You can get closer to God or Nature or whatever it is the highest things we value in a national park," says Burns.

The parks are the product of sacrifice and big dreams. Preserving them for the future will require dedication from the American people.

Burns' "The National Parks: America's Best Idea" premieres on PBS this fall.