Thanks to all of you for your suggestions and input! This forum is great!
Think I should make a few clarifications. Our first official destination is Zion National Park (if we come across I40, if we decide to head west on I70 we will go to Arches National Park first). We want to visit both these locations in Utah. Then we are headed to see some friends in Reno and we are trying to decide what is the best route,,,again, it will probably be determined by whether we are leaving from Arches or Zion...
After Reno we are headed to the Northern Oregon coastline. We plan to visit the coast from Newport to Astoria. We've driven this area many times but never with our RV. Then it's on to Portland and back home. Most likely it will be June by then and we will come home on I84/I90.
Thanks again for all your ideas and experience. We've had our rig 4 years(2008 Dodge 3500 and 2010 Jayco Eagle). This will be our biggest trip/adventure!