Some options:
1. Desert Rose RV Park in Fernley NV (Passport America park)
2. Flying J - Wells NV
3. Sweetwater Fairgrounds, Rock Springs WY (make sure there are no events there then)
4. Cheyenne, WY
5. Windmill State Rec Area, Gibbon, NE.
6. Omaha, NE
7. Bald Eagle Campground, Scott County Parks, Eldridge, Iowa.
OR I-80 Truck Stop Walcott IA.
8. Flying J, Lake Station, IN
I would wait to drop down to I-70 until after Indiana. Last time we were through there it was very rough and lots of construction. Maybe someone has a more recent update that can chime in.