When filmmaker Ken Burns was in Seattle recently, I had a chance to chat with him briefly. When I mentioned I'd visited Wind Cave National Park in South Dakota this summer, Burns said, "Oh, you got to Wind Cave" with the kind hushed approval that says you've done something special.

Burns seems to have a kind of proprietary feeling for national parks, as creative people often do for their subjects. His PBS series "The National Parks: America's Best Idea" reached over 33 million viewers. Seattle was in the top five markets for viewership. Burns told me he thought the uptick in park attendance was due to his series. Attendance at national parks and monuments was 285 million in 2009, up by 10 million over the previous year. The Obama family's high-profile visit to the Grand Canyon and free admission days also might have helped. The trend has been upward for a few years now.

This summer my wife and I took a road trip through 12 Western states and we surely helped 2010's attendance figures, spending time at Grand Canyon, Crater Lake, Petrified Forest, Agate Fossil Beds, Scotts Bluff, and the Little Big Horn, among others. These and similar preserves provide an incredible combination of nature and history. Wind Cave, just north of Hot Springs, S.D., and south of Mount Rushmore, was a park I'd barely heard of, but we found it a hard place to leave.

It is in the southern Black Hills where the ponderosa pines meet the prairie. It is the American savannah, with a large herd of buffalo, along with elk and pronghorn antelope and large prairie dog towns. The grass waves like the sea and hums with life, and there are wildflowers coloring the hillsides. Beneath your feet is a vast limestone cave system, largely unexplored, that is quiet, dry, warm, windy, and tomb-like. We took a special once-a-day tour of the cave and saw it as the original cave discoverers did in the 1880s: by candlelight.

The impression of Wind Cave is of a preserved piece of wilderness, a North America as you might have seen it had you been hunting with spears, or traipsing over unexplored terrain with Lewis & Clark. The pronghorn leave a kind of prehistoric impression, survivors from an earlier age with their lightning speeds and boxy heads. These "antelope" are unrelated to any other species still around. And the buffalo harken back to a time when their herds darkened the prairies with vast numbers and roamed as far east as New York, as far south as Georgia. They are enormous, wooly, intimidating, and beautiful. Everywhere, they seem to be posing for their portrait on the nickel.

But it wasn't long before I realized this wilderness wasn't so wild. In conversations with park rangers, talking around campfires, and reading park literature, it became apparent that Wind Cave National Park is largely a work of human creativity and management. Granted, wildness is part of the scheme; in fact, it's what the park's planners and stewards are aiming for. But nature in the park is being heavily steered by humans with a specific intention, much like any park, or zoo.

Wind Cave became a national park in 1903 and was the nation's seventh. The goal was not so much to preserve wildland but to restore it, and that required fencing it off and intervening so that grazing land, old homesteads, and mining claims could be returned to native prairie.

The buffalo at Wind Cave aren't from the area. They're largely descended from 14 buffalo donated by the New York Zoological Society in the Bronx in 1913, plus a few members from the Yellowstone herd. According to a recent study, the Wind Cave herd is rare, considered to be genetically "pure." That means it is one of only two public herds with no cattle genes, which are present to a greater or lesser degree in almost all surviving bison these days. All American bison were brought back from extinction with a breeding group of about 150 buffalo. In the late 19th century, ranchers began experimenting by cross-breeding them with cattle, thus the rarity of genetically pure buffalo.

Today, Wind Cave's buffalo are fenced off from a neighboring, less pure herd in adjacent Custer State Park. They are rounded up annually with the aid of helicopters, then genetically tested and checked for cattle diseases like brucellosis. The wild animals you see are carefully tended and bred, like a flock of prize sheep, albeit they remain fully capable of goring or stomping you to death.

The elk native to Wind Cave were the now-extinct Eastern Elk, so the park's herds come from Rocky Mountain elk imported for the job of repopulating the area. There are, in fact, too many elk for the park to sustain, so various means have had to be devised for removing them, such as gates that will let them out in winter, but won't let them back in come spring. Presumably, hunters will find them outside the protection of the park and thin their numbers.

There is an active program to protect the prairie-dog populations in the park from getting the plague, which has infected prairie-dog towns as close as 20 miles from the park. Rangers put tubes into prairie-dog dens and spray the adorable rodents inside with insecticide to kill fleas. The fleas can transmit the disease and could easily be brought in by one of the prairie dog's innumerable predators, like the coyote. The dogs have no natural immunity and the mortality rate can run to 100 percent, higher than a village in the Middle Ages.

One reason for the program is to protect a recently reintroduced prairie-dog predator: the rare black-footed ferret. This ferret, once thought extinct, was brought in to Wind Cave because the health of the prairie dogs is tied to their having predators that help keep their population under control. The black-footed ferret lives in prairie-dog dens, and seems to be a key to the town's complex ecosystem. The use of insecticide is designed to both protect them from the plague and to keep them from losing their primary food source. The ferrets are rarely seen even now.

Like a garden, the park is also aggressively weeded for invasive non-native species, like tansy, knapweed, and Scotch thistle. Over 100 such species have been identified in the park.

To keep a park like Wind Cave "wild" takes a lot of work.

Protecting wilderness has always been a bit of an oxymoron. Once you create an unnatural thing, like a park, you accept responsibility for managing what's inside the perimeter. And since parks are rarely complete and isolated ecosystems, it takes some doing, over time, to preserve what you have or restore it to something approximating an earlier state. And then, of course, there's the challenge of balancing the impact of millions of visitors, like us.

Wind Cave is not the only place where the human hand intrudes heavily. In our own Northwest backyard, we are quite busy reshaping natural areas. In Olympic National Park, fishers have been reintroduced, and some would like to bring back wolves. The mountain goats in the Olympics aren't native, and invasive plants are battled. We're also tearing down the Elwha Dam to restore one of the park's river systems, the largest undertaking of its kind. At Mount Rainier and North Cascades parks, they're fighting invaders like holly, ivy, and thistle. Rainier's lakes and rivers are full of non-native fish like brook and cutthroat trout.