Having been out west somewhat recently, I highly recommend the Grand Canyon, Redwood Forests in Cali, and Yellowstone. If you end up by Yellowstone, the Teton mountain range is absolutely gorgeous and isn't too far out of the way.
Pay attention to Yellowstone Park's season though... It "closes" somewhere between Sept. & Oct. No camping, and you're not allowed to just pull over there - overnight/all day parking only in approved areas. Camping was ofcourse completely closed weather related as i was there in October, but.... Yeah, lol, Yet another thing i missed because it was closed, haha. There's essentially 2 roads trough Yellowstone. They kinds make a football, anyway, the North Road closes earlier in the year - And it's got the cool shit, like geysers, and hotsprings, and the museumy-educational stuff... It was snowed in when I went through. The southern road was still a pretty drive, even if it too was white.
Grand Tetons were also quite beautiful... But not nearly as exciting as the bear... Kinds the highlight of that pretty but otherwise miserable drive.
I also most definitely agree that Redwoods in Cali are totally worth checking out. Nothing like em!