When Thomas Jefferson paid 20 shillings in 1774 for a limestone natural bridge that curved prettily over a tributary of the James River in Virginia, he told the seller, King George III, he was buying the land so that this "most sublime of Nature's works" would never be harmed or hidden from public view.

Buying a slice of pristine countryside simply to look at was a bit eccentric in a society that regarded unproductive land as "void" ground. Yet one of Jefferson's other purchases — the Louisiana Purchase — would become home to seven of the country's most majestic national parks and monuments, though the first wouldn't be created for more than a half century after Jefferson left the White House in 1809.

Ken Burns' six-part documentary The National Parks: America's Best Idea — to be aired on PBS stations beginning Sunday, Sept. 27 — chronicles the evolution of the idea that wild places should be protected. (A book with the same title, by Burns and Dayton Duncan, accompanies the film.) The documentary tells how Americans came to love the wilderness they once reviled as a godless waste. Against a backdrop of towering waterfalls, flaming volcanoes, and cascading glaciers, Burns tells stories of the men and women who devoted fortunes and risked political careers to preserve America's most sublime landscapes — the biggest trees, tallest mountains, deepest lake, and grandest canyons — by enclosing them in public parks that would last forever.

The film brims with Burns' grace notes: mountain music, old photographs, and timeless letters that present the history of the parks as a series of personal dramas. It swells with pride in the parks and may well be Burns' most celebratory work. In the process, however, it glosses over some of the darker moments. The expulsion of Native Americans from lands that became national parks rates a passing mention. And the ominous signs of climate change, which could create more havoc than wildlife poachers of yore, are not discussed at all.

Divine architecture

The parks drew their inspiration from the Transcendental movement of the mid-19th century and the works of Henry David Thoreau and Ralph Waldo Emerson, who recoiled from the materialism of the era. In contrast to their Puritan forebears, these thinkers saw wilderness as a more perfect example of God's architecture than anything man could hack out of it.

The parks gained political momentum for more secular reasons. The work of painters Albert Bierstadt and Thomas Moran and photographer William Henry Jackson awoke the public's interest. The railroads, foreseeing handsome profits from tourist traffic, provided a key endorsement. The act establishing the nation's first national park, Yellowstone, in 1872, refers to it as a public "pleasuring ground" and does not allude to its divine attributes.

Burns' film traces the disparate trends — the role of the automobile, for example — that both popularized and commercialized the parks. It is full of touching, even heartrending, tales of the people whose histories are bound up with the parks. But it's a long film, aired in six two-hour segments. There are too many testimonials, and when the Emersonian wind starts to blow, getting through it can be a slog.

Actor Peter Coyote does most of the narrating, with help from Tom Hanks, John Lithgow, Amy Madigan, and Eli Wallach; writers Nevada Barr and Terry Tempest Williams; historians William Cronon and Alfred Runte; and many others.

The best parts of the film deal with the muscular era of park building, from 1870 to 1940, when most of the famous parks and monuments — including New Mexico's only national park, Carlsbad Caverns — were established. It was the period when the evangelists of a budding environmental movement clashed with frontier titans over the fate of Yosemite and the Grand Canyon; when an old Indian fighter and buffalo slayer, Gen. Philip Sheridan, dispatched the cavalry to Yellowstone to secure the park from poachers and vandals.

Those were the days when a president toured a national park on horseback and didn't just drop by Old Faithful for a photo op. It was a time when conservation and conservatism were not mutually exclusive terms, when Republicans did not consider it an act of socialist treachery if the government pre-empted private ownership to protect a fragile landscape or a vanishing species.

In 1900, one of the most conservative members of Congress, John F. Lacey of Iowa, won passage of one of the toughest wildlife-protection laws ever enacted. Six years later, with the help of archaeologist Edgar Lee Hewett, Lacey sponsored the Antiquities Act, giving the president sweeping authority to create national monuments. Among the first were New Mexico's El Morro and Chaco Canyon. "Mankind must conserve the resources of nature, or the world will become as barren as a sucked orange," Lacey said.

Conflicting interests

In Burns' films, viewers look forward to the small treasures he digs up from picked-over mines. Here he unearths the story of Theodore Roosevelt escaping his presidential entourage to go camping with John Muir in Yosemite National Park in 1903. Muir was already America's most famous environmentalist, and Roosevelt was well on his way to becoming conservation's greatest friend in the White House.

The two, meeting for the first time, marveled at the scenery and reportedly quarreled like cronies. Roosevelt noted that Muir showed "little care for birds and birdsong." Muir took the president to task for his love of hunting. "Mr. Roosevelt, when are you going to get beyond the boyishness of killing things?"

Sacred ground to Muir, a national park was to Roosevelt the heartland of democracy, refreshingly different from Europe's exclusively aristocratic sanctuaries. Ernesto Ortega, the director of New Mexico's State Monuments and a former National Park Service official who was interviewed for Burns' documentary, reminds us that America was the first country to open its great parks to all classes.

Not everyone warmed to the experience. "I am in the Yellowstone Park and I wish I were dead," wrote Rudyard Kipling in reaction to the "ghastly vulgarity" of late-19th-century American tourists.

And yet many of these public parks would not exist if it had not been for wealthy philanthropists such as both President Roosevelts, John D. Rockefeller, and Stephen Mather, the first director of the National Park Service. Rockefeller was the archangel, contributing nearly $45 million for the purchase and upkeep of park land from Maine to California. Mather was the dynamo. He was a super salesman responsible for the success of 20 Mule Team Borax before becoming head of the new Park Service in 1916. His tireless stewardship led to the formation of 23 national parks and monuments by 1930. His proprietary rage at anyone who would deface the parks once caused him to order the dynamiting of a sawmill owned by the Great Northern Railway in Glacier National Park. Mather lit the fuse.

But if the national parks represented America's best idea, the evolution of this idea was a messy business. What emerged was a mix of pantheism and commercialism, preservation and exploitation, movie theaters and shopping centers cheek by jowl with nature trails and generators drowning out the sounds of waterfalls.

Before the parks welcomed the masses, they ran off thousands of people who had made their homes or their livings in the lands that became Yosemite, Yellowstone, the Everglades, and Great Smoky Mountains National Park. The federal government bought the eastern section of Glacier National Park from destitute Blackfeet Indians for half the tribe's asking price and then broke a promise to allow the Indians to hunt and cut firewood in the park. This sad chapter in the history of the national parks is missing from the film, though it is briefly covered in the accompanying book.

The law establishing the National Park Service called for the protection of native wildlife, but it took decades and the thankless struggles of park scientists George Melendez Wright and Adolph Murie before the law was taken seriously. In the interim, park rangers shot and poisoned coyotes. Yellowstone's wolves were exterminated in the 1920s. (They were reintroduced in 1995.) At one time, according to the Burns and Duncan book, Yellowstone rangers were "ordered to go to the nesting grounds of white pelicans and stomp their eggs, because it was feared that grown pelicans deprived anglers of too many fish."

When it was built, Glacier Park's Going to the Sun Highway opened up the park's soaring alpine interior to the traveling public — and all that came with it. Atop Glacier's highest pass, a parking lot became a prime wildlife viewing area after mountain goats were drawn there by the sweet taste of antifreeze.

Exploitation and protection

Burns raises the question that has dogged wildlife policy from the outset: how to exploit the entertainment value of wild animals and protect them at the same time. But his upbeat film doesn't really get to the heart of the matter — our enduring ambivalence about the value of nature itself.

If John Muir and Theodore Roosevelt found spirituality in granite pinnacles, Ronald Reagan and George W. Bush saw more value in what could be mined or pumped from the rocks. Roosevelt described Yosemite's giant sequoia trees as "pillars of a mightier cathedral than ever was conceived" by man. Reagan asked, "If you've looked at a hundred thousand acres or so of trees, you know a tree is a tree; how many more do you need to look at?"

Today, the parks are faced with a multibillion-dollar maintenance backlog. Skimpy budgets have left too few rangers to cope with a host of modern menaces, including pot growers, artifact thieves, and armed scofflaws tearing up the backcountry aboard all-terrain vehicles and snowmobiles. Oil and gas wells, uranium mining claims, and expanding subdivisions crowd park boundaries, marring views and destroying wildlife habitat. Annual attendance is down 12 million people from a decade ago.

In New Mexico, you don't have to look any farther than the gang graffiti on 5,000-year-old rock art in Petroglyph National Monument or listen to demands that the Valles Caldera Preserve, an ideal setting for a park, be required to pay its own way. Mark Twain once warned, "Nothing dollarable is safe."

Will America's best idea survive? As author Roderick Nash mused in Wilderness and the American Mind, it is possible that our need for the wild "may be a transitory, frontier-related enthusiasm that Americans will outgrow."

Burns reminds the pessimists that many of the challenges that seem so formidable today are not new. The people of his film have grappled with them for a century, often successfully. Along with the stories of famous philanthropists and politicians are stirring accounts of ordinary citizens who devoted their lives to saving the parks. Some died broke after forgoing income or using up family fortunes to preserve park land. George Dorr, the first superintendent of Maine's Acadia National Park, spent his considerable inheritance acquiring land for the park. There wouldn't have been enough money left for Dorr's funeral if a trustee of the family estate had not set aside $2,000.

Lancelot Jones was the son of a former slave and a fishing guide on Florida's Biscayne Bay when he learned of a multimillion-dollar plan to turn the bay's lush mangrove islands into a seaport. Jones helped defeat the plan, and when President Lyndon Johnson intervened, Jones became the first landowner on the islands to deed his property to the new Biscayne National Monument, now a national park.

Chiura Obata, a young Japanese immigrant, began crafting lovely woodblock prints of Yosemite in the late 1920s. Dazzled by Yosemite, Obata spent months exploring and painting the scenery that he came to call dai-shizen or "great nature." His work would catch the eye of first lady Eleanor Roosevelt, but not before Obata was sent to a World War II internment camp in Topaz, Utah.

Obata said he was sustained by his memories of one of Yosemite's mighty "grandfather" trees. "In such times I heard the gentle but strong whisper of the Sequoia gigantean," Obata wrote. "'Hear me, you poor man. I've stood here more than three thousand and seven hundred years in rain, snow, storm, and even mountain fire keeping my thankful attitude strongly with nature — do not cry. ... You have children following. Keep up your unity; come with me.'"

Artist George Catlin, who traveled across the Great Plains in 1832, may have been the first famous American to call for "a nation's park" lest all of America's wilds "fall before the deadly axe and desolating hands of cultivating man."

The notion has persisted that national parks are islands in the empire, welcome obstacles to Manifest Destiny. Many modern environmentalists take comfort in the belief that the parks, or at least the wilderness within them, offer refuge from the real America. Yet it's hard to imagine Theodore and Franklin Roosevelt as counterculturists. "There is nothing so American as our national parks," Franklin Roosevelt said in 1936.

Burns' film teems with images from the golden age of park building: dark-suited dignitaries assembled on Yosemite's high ground, crisply uniformed rangers, grand hotels, and lines of jam-packed Model T's touring Yellowstone. Only in contemplating events of the past decade — events largely missing from the film — do you wonder if the parks have lost some of their allure.

Lyndon Johnson's visionary Secretary of the Interior, Stewart Udall, who was responsible for the Redwood, North Cascades, and Canyonlands National Parks, among many others, once warned, "what we save now may be the last we save." Udall's words were prophetic enough. The Reagan era saw just one new national park and a handful of national monuments created, including El Malpais in New Mexico.

The parks today

The congressional revolt of 1994 ushered in a conservative majority
whose members viewed wilderness quite differently than did Republican conservationist John Lacey. Some members of the new Republican majority called for the repeal of the Antiquities Act that Lacey had sponsored.

After nearly eight years in office, President George W. Bush had created several national historic sites and memorials but no new parks. Meanwhile, his administration effectively industrialized millions of acres of publicly owned wilderness, much of it next door
to national parks.

But Bush had a surprise in store. Invoking the Antiquities Act in January 2009, he established three new national monuments embracing nearly 200,000 acres of the Pacific Ocean and creating the world's largest marine protected area. Critics said he did it to spruce up his record before leaving the White House. Maybe so. But whatever the motive, Bush bent a knee to that old-time religion, the one that Emerson and Muir preached and that Burns salutes. Apparently, it could still move a president — even a non-believer.