When Wallace Stegner wrote that America's national parks were "the best idea we ever had," he did not mean "It's a good idea to steer your RV through Yosemite with the A/C on." Over the past decade our great playgrounds have devolved into drive-through tourist trapseven as visitation held steady at around 275 million, backcountry trips plummeted by 13 percent. But change is afoot. The government is pouring $920 million into the parks to rebuild roads and relieve congestion (read: less pre-playtime spent sucking exhaust). Come this fall, Ken Burns's latest PBS mega-series will give the parks 12 hours of high-profile lovin'. Throw in a recession that has adventurers planning vacations closer to home and you've got a recipe for what we prefer to call a revival. How to take Yellowstone & Co. back from the map-and-camera crowd? Start with our guide to the wildest, least-trafficked spots in America's last best places.