That;s a really big area. By four states I'm guessing that you're including Nevada, Utah, Arizona, and California.

What time of year are you traveling?

Check in here under the various states for trip reports and other information.

As for camping - with an RV - don't know how much tht might limit availability - but would certainly check ahead at some of the areas/campgrounds you intend to vist and see how busy they will be. In May - it shouldn't be too busy - but who knows for sure?

We were able to camp (with a small tent) in both Bryce, Canyon and the Navajo National Monument (outside of Kayenta, AZ - close to Monument Valley) at the end of last June - without reservations - but not sure how it works for RV spaces?

One thing I would recommend is that if you are moving from one area to another - start early - as the campers on the road start to become more numerous as the day goes on.

I've finally had my morning coffee and noticed the part about May! That's a pretty good time of year for a lot of the Southwest. It'll be hot in southern Arizona and Death Valley but should be good weather for southern Utah, northern Arizona and the Grand Canyon.

You could do a loop from Las Vegas to Zion, Bryce, Capitol Reef, Arches, Canyonlands, Monument Valley, Canyon de Chelly, the national monuments in northeastern Arizona (Sunset Crater, Wupatki, and Walnut Canyon) and the Grand Canyon. Then back to Las Vegas. You could also add in some state parks in Utah (Snow Canyon, Goblins, Goosenecks).

With 21 days you have time to see a lot, especially if you aren't doing a lot of long hikes. I've done SW loops using Denver, Phoenix and Santa Fe as my starting points (flying into ABQ). You can easily fit in Sedona and/or Santa Fe in your loop and I love them both. Definitely plan to see Mesa Verde in Colorado and you have time to loop around and see Great Sands NP as well. By two weeks in the mountains, you may be ready for a change in scenery and see some of the Colorado mountains.

Okay, here's a figure eight looping route that I'd used if I were going to spend that amount of time out of Las Vegas.

- Las Vegas
- Hoover Dam
- Sedona, AZ
- Grand Canyon NP
- Mesa Verde NP
- Great Sand Dunes NP
- Santa Fe, NM
- Canyon de Chelly
- Arches NP
- Zion NP
- Las Vegas

See the other things you want to see along the way. I like Meteor Crater and a drive through Painted Desert NP. You'll love Monument Valley and stay overnight there if you can. A lot of people think Four Corners is too touristy, but as a tourist I want to stop. I'd even add in the North Rim of the Grand Canyon (in addition to the South Rim). There's a lot of possibilities to add in but IMO that figure 8 loops lets you see a lot of different kinds of things - and you have plenty of time to explore. You may not want to move around that much, but it's the route I'd take.

The road into the north rim of the Grand Canyon might be closed in May. It would depend on the winter snowfall.

That's true. The lodge at the North Rim opens on May 15th and the campground is to open in mid-May. There's a chance that snow could affect access - but the NPS plans for a mid-May opening.
https://reservations.foreverresorts.com/ReservationCalendar.do?propertyKey=181
http://www.nps.gov/grca/planyourvisit/cg-nr.htm

I was thinking more along the lines of the South Rim but if the North Rim were open that would be a nice place to visit.

I would definitely go to the South Rim - if you've not seen the Grand Canyon before. But if there's time, I'd add in the North Rim nearer the end of the trip - mainly because it's so different and I like it so much. IMO it's what I imagined a "national park" to be in my childhood.

Hy Guys..wow I wrote this before going to bed and here you all are. So many thanks. I spent a lot of yesterday looking at the maps. We visited this area twice before for short breaks in a car and I really fell in love with the area. remember about the N Rim - we drove all the way round and it was shut in (opening the next day!!) A ranger in the petrol station gave us a map to explore some forestry roads and we did manage to find a vantage point. Loved Green River at Canyonlands and still think that is the best view I have ever witnessed and we did see S rim as well. Probably give Bryce & Zion a miss as we spent 5 glorious days there and passed through Death Valley on our way up to SF via Mono Lake.
My husband had an RV for a year travelling the States 13 years ago. He figures we should get quite a few nights free/low cost camping. This will be a new experience for me. Are there any roads that one should avoid?
I love photography and so that is my wish to capture some magnificent vistas and range of colours.
Shal note some of these suggestions and look at the figure of eight loop! Thanks all

If you don't need hook-ups you have a wealth of options at national forest campgrounds. We used to do that a lot - but we were tent-camping and they were very primative (sometimes only pit toilets). Since you have your RV you should be fine if you are boondocking. I would make reservations at national park campgrounds that don't have private campground alternatives. One of our favorite campsites ever (when traveling with kids) was the KOA Durango North - but I don't think it's there anymore, at least the one we went to. In May, before schools are out, should not be that bad. You could easily make reservations at places you REALLY want to see and then "follow your noses" in between those locations. It's my favorite way to travel.

BTW - we had a senior/half price rate camping in Bryce (don't know if you qualify) and it was free at the Navajo National Monument (first come first serve) but we left a donation.

And totally agree - that since you are relatively self-sufficient in a RV - you should be able to google away and find plenty of options.

In addition to the suggestion of the Painted Desert - where they have a good visitor's center - you can drive south of 40 - to/through the petrified forest and they have other interesting things to see such as petroglyphs, etc. http://www.nps.gov/pefo/index.htm

And if you like to look up at canyon walls - you could consider a half day float trip from Page - down the Colorado River. Here is one site and there are others: http://www.raftthecanyon.com/

tomsd is right. I said "Painted Desert" above when I meant "Petrified Forest". Sorry.

I also love stopping at the Hubbell Trading Post when I'm in the area. It's not a "big" attraction but one of my favorites - http://www.nps.gov/hutr/index.htm

Another favorite is the Cameron Trading Post on the east side of the Grand Canyon (south rim). We spent hours there one time while my sister shopped for Navajo rugs. The meal in the restaurant was excellent and the fry bread was the best food of the trip.
http://www.camerontradingpost.com/restaurant.html

Hubbell Trading Post is historic although they sell rugs, etc.
Cameron is commercial with a hotel, restaurant and shop.
(just to compare the two). I like both.

My favorite souvenir of the trip was picking up a CD at Cameron of Mary Youngbloods's "Beneath the Raven Moon". It became the soundtrack of that trip. GREAT driving music.

LOL Starrs: It's great to find a "traveling" album - and when my niece was a teenager (egads - she's now a college senior at UCLA) - we loved driving around the Western states listening to Izzy's Facing Future album. http://en.wikipedia.org/wiki/Facing_Future

I first saw Izzy and his brother - in the late 70's - when they were playing as the Sons of Niihau - at a concert in Waimanolo. Think I was the only haole in the house.
and the little ukeleles looked like toothpicks in their hands.