In 2003 I made this trip by motorcycle.
Having seen Olympia National Park
and the Washington coast on a previous car trip,
which is certainly a worthwhile choice,
I opted this time to ride from Spokane
down to the Columbia River and followed it to Astoria
and down the Pacific Coast Highway to LA
making a huge loop of the western half of the U.S.
Ride report can be found here, Hell Bent for Leather.
Assuming you head up the Olympic Peninsula on 101, highly recommend you take the ferry from Port Townsend to Whidbey Island. At that point you can pick up SR 20 and take the North Cascades highway east. It's spectacular that time of year and the east side of the mountains will provide a dramatic contrast with the peninsula.
It's so so so beautiful on the Olympic peninsula. Check out Hurricane Ridge, the Sol-Duc hot-springs and the most essential stop is Cape Flaherty, the northwesternmost point of the contiguous US.
I will be traveling with my travel trailer.
I have about 2 months.
I really like the diesel, getting 18-19 MPG towing at 65-70,
my first stop is going Amarillo (10 hours) 600 miles, Houston - Amarillo
second stop is going to Moab, UT (11- 12 hours) 650 miles, Amarillo to Moab UT.
don't know were is going to be 3rd stop .
but I need to stop and setup based camp on the 4 day for a week stop . any suggestions were I can setup a based camp for 5 days ?