Yellowstone National Park’s is America’s oldest park, and many might say its grandest, too. This century-old natural landmark spans three states and a supervolcano, and has geothermic features such as geysers and hot springs that are found in few other spots on Earth. Yellowstone hikes will bring you past these and many more natural wonders, leaving your legs aching and your jaw agape. The Greater Yellowstone Ecosystem is one of North America’s only undisturbed ecosystems left, and backpacking in its pristine backcountry is a truly unforgettable experience. If you want a smaller (though no less rewarding) slice of Yellowstone life, check out the 20-mile trek to Electric Peak.