Seat24A wrote:Since you mentioned NPs and RVs, I would recommend the ones in Utah - Arches, Bryce, Zion, and Canyonlands. The scenery is incredible and there are plenty of campsites (not just the big ones in the parks, but also some state ones off the beaten track). We went in early October and the weather was still good, but much less crowds.
The Grand Canyon and Yosemite NPs are "must see" places, but also check out some of the less visited parks like Joshua Tree and Sequoia/Kings Canyon.
This is exactly my opinion. Zion is one of my all time favourite parks, as is Joshua Tree. The others mentioned are all fantastic and highly recommended from me as well.
If you're going to more than a couple of national parks, be sure to get an annual pass (http://www.nps.gov/findapark/passes.htm). It's $80 and allows 2 signees. I'm not sure how it works if both signees are driving separate vehicles and entering at the same time. Most parks charge an entry fee in the neighbourhood of $17 just to drive in. The pass is also good for discounted camping in BLM operated sites and quickly makes up its value. We went to City of Rocks (Idaho), Arches, Bryce, Zion, Grand Canyon, Death Valley, Joshua Tree, Yosemite in one trip last summer and would have well exceeded $80 in park entrance fees alone. The pass will still be good for our next trip to Zion, Bryce, Antelope Canyon, Mesa Verde, and Arches later this summer when we're back from Europe.