On Sunday evening PBS will air Ken Burns’s much anticipated documentary, The National Parks: America’s Best Idea. News outlets and blogs were filled with reviews on Friday, a fitting end to a summer awash in news of our nation’s parks.

In early June, the National Parks Service announced that it would, for the first time, waive entrance fees on weekends in June, July, and August in an attempt to attract frugal vacationers during the recession. That spawned numerous national and local articles extolling the virtues of traveling close to home. In early August, Burns did a press tour that produced an early, sparse round of reviews of his documentary. Two weeks later, parks coverage reached its zenith when the Obama family visited Yellowstone and the Grand Canyon.

Whether or not all the attention will matter for the parks, embattled by a lack of funding and by climate change, or the American public, accused of suffering from “nature deficit disorder” and “videophilia,” remains to be seen.

Two days before the First Family’s trip to the western parks, the National Parks Service announced that total visits to the parks during the first half of 2009 were almost 4.5 million higher than the same period in 2008. An Associated Press story about the “nearly 4 percent” (3.5 percent on the nose) uptick got wide play, characterizing it as the “upside of the economic downturn.” In July, Yellowstone had a record number of visitors and other parks posted their highest figures in a decade. At the end of September, total annual visitation was still on track to be 3 to 4 percent higher than a year ago.

Great, right?

Not so fast. While Burns was promoting the country’s “best idea” (after equal rights, of course) in early August, New York Times columnist Nicholas Kristof took his eleven-year-old daughter backpacking in Oregon and “kept thinking of something tragic: so few kids these days know what happens when you lick a big yellow banana slug.” Kristof saw it as a sign of what Richard Louv called “nature deficit disorder” in his 2005 book, Last Child in the Woods.

A lack of awareness of the fact that Frenching a slug will make your tongue numb is not the best metric for gauging natural exposure, of course, but to support his point Kristof added that “the number of visits to America’s national parks has been slipping for more than a decade.” Fortunately, that statement is a bit misleading.

Visitation over the last five years was better than it was in the early to mid-nineties. The National Parks Service makes visitation statistics readily available on its Web site. Pouring them into an Excel spreadsheet quickly shows that annual visitation has remained basically flat for the last for last twenty-five years, with peaks in the late eighties and late nineties. In 1987 and 1999, just over 287 million people visited; in 2008, just under 275 million did. In other words, last year was well above average for the entire period of the park service’s data, which goes back to 1979. It was just under average for the last decade.

Understanding this, one might view the recent ten-year decline as part of the normal statistical fluctuation. In an early review of Burns’s documentary, Timothy Egan, another Times columnist, noted that the parks “still draw more people than Major League Baseball, the National Football League, the National Basketball Association, and Nascar combined… The problem is that 10 years ago, the parks attracted bout 12 million more visitors than they do today.”

He could have also written that twelve years ago, they attracted ten million fewer. But there’s a catch to total visitation numbers, at any rate.

Curtis Brainard is the editor of The Observatory, CJR's online critique of science and environment reporting. Follow him on Twitter @cbrainard.