289 to 89A to 89. In Flag you can continue on 89A to Sedona or take the 17 (interstate) down to 179 and double back to Sedona. Remember, you have this ditch called the Grand Canyon between Zion and Sedona so your options are very limited. This is a very well traveled RV route so you won't be alone. Just plan for fuel stops and be prepared for possible inclement weather.
