The Virgin Gorge is the very steep and rugged canyon that runs from Utah, through Arizona, and ends about 20 miles before you go into Nevada. Interstate 15 runs through the gorge and at the time it was built was the most expensive portion of the Interstate system that did not run through an urban area. For a significant portion of the route they highway engineers built the freeway on bridges over the virgin river. It is a short but beautiful canyon, that is filled with multiple varieties of cactus.