Complex sentence: The most-visited national park is Great Smoky Mountains, with over nine million visitors in 2011, followed by the Grand Canyon, with over four million; in contrast, fewer than 5,227 people visited the remote Lake Clark.
Split into simpler sentences: The most-visited national park is Great Smoky Mountains, with over nine million visitors in 2011, followed by the Grand Canyon, with over four million. In contrast, fewer than 5,227 people visited the remote Lake Clark.