Indiana to Oregon

There are several military Fam Camps on your route.

GM

I-70 from Denver to/through Utah and I-80 through Wyoming will be a******shoot that time of year. Wyoming is known for its wind and blowing snow and I-70 passes through mountains prone to heavy snow into late June.

However, that time of year would be a great time to visit. Moab and Zion easily hit 100 degrees most of the summer. The spring will have much nicer weather.

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!

You might be able to make some decisions a month ahead of time... as far as whether or not this or that route is possible.

This link is for planning your trip a week ahead or a day ahead of what you are going to do. Save it. It will come in handy.
Weather Underground Road Trip Planner

play with it well ahead of your trip. Learn how to use it. Set your departure date and then check departure times to get the best road conditions for that day.
Learn how to check it against wind, elevation and radar.
Elevation makes a difference whether moisture is snow or ice.
WIND does too.

using the link I gave you, you can make a careful choice whether to roll the wheels sooner or wait a few days... or even stay put a few hours to get better road conditions.

In late April there is no reason to go that far south and run I-40. If you want to run I-70 you'll be able to. AS always, watch the weather forecast. But remember that the further north you run, the fewer campgrounds & sites that will be open.

Not only snow but 6% grades for 5 or six miles up and down, snow chains are
required in some western states till April. Lots of good camping places out
here, I always key in 8.5 or better on the GS trip planner and never had a
problem....

We live in Indiana too and just completed(yesterday) a 7k+ mile, 50 day trip out west to include Portland. We also did Burns and Onterio,OR., Great Falls,Missoula, Rapid City, Cheyenne, Lincoln,NE., St Joseph,MO., Springfield,Ill. just to name a few. We used all kinds of roads,state,federal,interstate. It was a great trip. We did no real planning except to get to Great Falls in 6 days. During the trip we stayed at 4 different Air Force Famcamps. Have a great trip.

Break your question into several pieces. The direct route to Oregon is very different from one that includes Zion or Reno.

Reno is about 600 miles away from Portland. How much of a hurry are you?

No matter which way you come, you can hit snow.
Be prepared! What the weather!
Most of the east-west interstates have the potential of snow.
Entering OR on I-84 or I-5 could have snow.