The US has 63 national parks, and if you only know the greatest hits, you know maybe a dozen of them. Everyone funnels into Yosemite, the Grand Canyon, and Yellowstone, takes the same photo from the same overlook, and waits in the same line for the same parking spot. Meanwhile, dozens of parks just as worth your time sit nearly empty, scattered through deserts, islands, swamps, and canyons most people never think to visit.