There are over 2,000 catalogued arches in the park, the highest density of arches in the world. They range from three feet to 306 feet long (passage of light through three uninterrupted feet is the minimum length to be classified as an arch).

Landscape Arch is possibly the longest known natural arch in the world (it's a toss up with Kolob Arch in Zion, the tallest arch is in China). It's span of 306 feet rises 105 feet above the ground. It's narrowest point is under 6 feet.