\" \" Nymph Lake at Yellowstone National Park looks lovely in winter. But just because it's winter doesn't mean you should give up on visiting America's national parks. The first national park in the United States — and in the world — Yellowstone National Park in Montana, Wyoming and Idaho, was created in 1872 when Civil War hero and U.S. President Ulysses S. Grant signed the Yellowstone National Park Protection Act. The act jumpstarted a trend — there are now 58 national parks (and hundreds of memorials, rivers and related sites) scattered throughout America. Visitor numbers are booming, and in 2016, the National Park Service logged 331 million recreation visits, a second straight record-breaking year for visits [source: National Park Service].