Great Smoky Mountains park is the most visited national park in the United States with more than 9 million visitors a year. Yes, it can be crowded on weekends in July and October, the peak of leaf season. But with more than 800 miles of trail, it’s easy to leave behind the maddening crowd. Beyond the easy-on-the-eyes landscapes, the park also offers opportunities to see a variety of wildlife, from black bears to salamanders.