OREGON AND WHASHINGTON

I assume your talking about the Cascades. If I was planning a trip through that area, I would think I would start at Crater Lake and then drive up Hwy 97 north. You didn't mention what kind of camping you want to do, the Forest Service has a lot of dry but wonderful campgrounds around Sisters, and Mount Hood. Crossing into Washington, still on 97, I would go as far as Hwy 12 West and check out some of the great camping around Mount Rainier and then I would return to 97 and drive up as far as Lake Chelan and if you have time, as far as Hwy 2, crossing on it to I5 and over to the Olympic Mountains.