Columbia River camping
On our last year's trip back from camping around Eastern Oregon (Hells Canyon area - gives you an idea of our preferred "exploring" style), discovered by fortuitous accident a great campsite on our way home.
Crow Butte Park, along Wash SR14, maybe about 20km West of I82 crossing the Columbia River from Umatilla OR to Plymouth WA.
It's on an island in the river, connected by a causeway. From the campground, short hike up a hill to overlook the Columbia.
Other random noteworthy spots (not necessarily campsites) "discovered" on this trip: John Day Fossil Beds; Oregon Trail Interpretive Centre, Baker City OR; OR SR86 & SR350 from Baker City past Hells Canyon to Imnaha & Joseph (several great Forest Service campgrounds along there); and the town of Joseph itself, which has "reinvented" itself as a bronze casting/foundry centre.
Lotar & Wendy
"Sit loosely in the saddle of life" (Robert Louis Stevenson)