It's been exactly 100 years since President Woodrow Wilson signed legislation that established Zion National Park in southwestern Utah. Fewer than 2,000 people visited back in 1919 due to poor road conditions and lack of trails. These days, the park has the opposite problem—with more than 4 million people coming each year, crowds create long lines for shuttles and clog popular areas such as the Narrows. Part of Zion Canyon, the Narrows can be seen from a paved path. But many people like to experience it up close by hiking in the Virgin River, and it can get crowded at peak times since it's—as the name implies—narrow.