10 national park experiences of a lifetime

Travelers typically speak of Yellowstone, Yosemite or the Grand Canyon with a sense of reverence. These, along with the other 398 units managed by the National Park Service, preserve special places with spectacular landscapes and memorable activities. Some park experiences are well-known, such as rafting down the Colorado River through the Grand Canyon or strolling Yellowstone's Upper Geyser Basin to witness the eruption of Old Faithful. But plenty of others are overlooked.  Go there...