If you want to stay in the US, go to Oregon. Three years ago my family flew to Portland and rented a van. We drove to the coast and followed it south through the entire state. There is a lot of seafood, beaches/hiking, sand dunes, sea lions, gulls, deep-sea fishing, and the scenery is breath-taking. We took someone's advice and drove further south into Crescent City, CA, where we drove through a park of redwoods (free). They were enormous, but not as big as the Sequoias. Kids had a blast...I even got up at dawn while we were there and went down to the beach and poked through the tide pools. I collected crabs and starfish there (DON'T try to take those on a commercial flight! LOL) Then when we returned north, we went through the heart of the state, stopping at Crater Lake, Mt. Hood, and at the north end, we drove west along the Columbia River, which separates OR and WA. Everything, including the weather, was perfect. The best thing was that we didn't feel like tourists, not even in Northern CA. It was all farming country with lots of cattle and really (surprisingly, after all I've heard about CA) down-to-earth kind of people. I'd take that trip again anytime!