You mentioned Pendelton, so I sort of assume your coming north on 395? Great road trip. Be sure to plan a night at Goose Lake State Park. No reservations, 20A water and electric. One of the hidden gems on the Oregon State Park system. Be sure to visit Cam Wha Chang historic site in John Day. Stop at one of the parks between the Dalles and the entrence to the gorge. And spend a day exploring the old hiway. Lots of water falls to visit. If you like hiking there are a lot of trails. At Portlands east side head north on I205, connect to I5 north. At Longview,WA follow the signs to the coast. You will cross the bridge and pick up US30 west to Astoria. FtStevens state park. Be sure to have reservations. Bow picker in Astoria is the best fish n chips. Plan a couple of days to explorw the historic fort stevens and historic FtClatsup. Home for Lewis and Clark expedition the winter of 1805/6. Near Tillamook you can spend a night or two at Netarts Bay RV park. Try for one of the view sites. Farther south is Salmon Harbor at Winchester Bay. Great park right on the bay with easy dune access.