Russell
It's quite a few years since we did this, but the company we used, twice, seems to be still trading. Try www.caravanabroad.co.uk Our first trip was on the west coast, starting in LA, then Grand Canyon, Zion, Bryce, Yellowstone, Tahoe, San Francisco, Big Sur, LA. As weel as sights and cities we also went to Disney, Six Flags, Raging Waters, Universal Studios, Hurst Castle - the kids were early teens. Did about 4000 miles in four weeks. USA is made for big RVs - drive-through camping pitches, full hook-ups, accessible parking lots etc. Parking in San Francisco was a challenge though!