Yellowstone National Park
Oldest National Park: Yellowstone National Park, 1872
With a flourish of the pen, Ulysses S. Grant changed where kids spend their summer vacations forever when he created the world's first national park. Yellowstone was made up of pristine wilderness straddling the Montana, Wyoming, and Idaho territories. (Tthey weren't states back in 1872, and the federal government oversaw the park until the National Parks Service was created in 1916.) Today, Yellowstone continues to be the system's bubbly, geyser-riffic, and wildlife-filled emblem of eco-consciousness. There is some controversy when it comes to which park is technically the oldest, though. Hot Springs National Park, southwest of Little Rock, Ark., was made a "government reservation" back in 1832, but didn't join the parks system until 1921.
Price: $25 per vehicle.