What a great trip for your whole family:) I have made the same general overall trip and given your itinerary I would suggest the following plan to "deviate from" allowing for adjustments as you make the trip.
1. Freemont to the Indio area.
2. Lv. Indio in the early morning to Phoenix to avoid the heat.
3. In Phoenix the Heard Museum is great and will be of interest to the kids. Lv. Phoenix in the early morning going north on I-17 to I-40, then on to the South Rim of the Grand Canyon.
4. cont. on hwy 64 to hwy 89 to Kanab then visit the north Rim of the G.C.
5. cont. to Zion and Bryce national parks.
6. then take I-15 north to Yellow Stone National Park
7 From Yellow Stone take I-15 to Spokane
8. Take Hwy. 2 to I-15 then north to Whidbey Island. Riding the ferries is one of my favorite activities.
9. You can take take I-5 south to Seattle to see the Seattle Dome and Fisherman Market etc.
10. Or you can load your trailer on a ferry to Port Townsend. the kids will love the ferry.
11, continue south on 101 to Long Beach. There is a 3 blk. long amusement center the kids will go crazy with.
12. cont. south Seaside to an RV park called "Circle Creek". Park the trailer. Now you drive around and sight see in Astoria, Stevens National Park, Cannyon Beach or a short 2 hr. drive in you want to sight see in Portland.
13. Cont. south to the famous Tillamook cheese factory,
14. Cont. south to Winchester Bay. 3 RV parks. Kids will like the sand dunes and you can rent sand vehicles to ride in the dunes.
15. South to Coos Bay. Stay at the Mills Creek RV park at the Casino. Go to Charleston and see the Botanical Garden.
16. Rv Parks in Brookings right on the ocean
17. South to see the Giant Red Woods.
18. south to Mendocino.
There are many sights and little towns to visit all along the Washinton and Oregon coast to visit. Strongly recommend you make reservations NOW for your whole trip as you will be hitting the high season for RVers. Reservations can always be changed or cancelled. Make sure you have an active Emergency Road Side Service plan to avoid issues if your rig breaks down or you have tire problems:):) Email me privately if you have other questions about the above trip.
