When you take the Mt. Carmel Junction-Zion National Park road, you enter into Zion National Park from the east side of the park. This is by far the most dramatic and beautiful road to take, however there are restrictions on the road, and be sure to check it out the National Park's FAQ for more information, cause there's no place to turn around if you get stuck there.
Walt and I were so completely taken by it that we had to make one of the first movies we've made with the Canon 1Dx. This is shot with his favorite wide-angle lens, on his fabulous gimble tri-pod.
Enjoy!