With the sagging economy, Americans are vacationing closer to home and the national parks are taking a beating. But that's been true for a long time. Threats include development near the Everglades, air pollution in the Great Smoky Mountains, and overcrowding in Yosemite Valley. Forget preserving the parks in a "pristine condition." Watchdogs say it's now a matter of repairing the damage before it gets worse. We hear why the next few months could be critical to the future of one federal institution most Americans really love.