Indeed, you guys have to start booking! I know Grand Canyon Village is pretty much booked for October. The gateway towns may still have rooms.

Either of those two are great at that time of year, and either is manageable on a 10-day trip. You see questions here from folks trying to do that in 3 days, utterly insane in my humble opinion.

Obviously Yellowstone / Tetons will be much cooler then, with even possibility for snow. But you could luck out with a high pressure system parked over the region, and have day after day of perfect weather. Fall is also a prime time for the desert southwest.

So I'll be no help on your decision, you can't go wrong either way, but you do need to get moving on reservations! Good luck and have a great trip.

You could do either route if you flew to SLC. Renting a car and staying in motel rooms and eating at restaurants makes the most sense. If you rent an RV you get lower gas mileage, cook for yourself (including dishes and dumping the holding tank).
It should be a bit warmer in southern Utah than in NW Wyoming at that time. I don't expect snow in Yellowstone, but it could happen.

http://www.nps.gov/yell/planyourvisit/open_closedates.htm

That is a link to the opening/closing dates of facilities within Yellowstone. Most lodging is closed by October, including campgrounds.

If you are willing to restrict yourself to the few available lodging options for your time frame, I would choose Yellowstone.

Lodging at the Grand Canyon typically books up months in advance but there are frequent cancellations. I would think you'd have better luck finding a hotel room/rv spot there than in Yellowstone.

Personally I think you're better off renting a car and finding a hotel room/cabin rather than getting an RV. If you aren't used to driving an RV it can be tricky, and they are much slower and less efficient than a car. Would you really want to go to Yellowstone for a week, get an RV spot but then have to stow everything away every day so you can drive around the park?

I'm originally from MA, and the visit I had to the Grand Canyon (early summer) surprised me by feeling somehow like the New England shore! Crazy I know, but the breezes felt the same, and there was even a flowering bush that smelled (but didn't look) like honeysuckle...

We packed a small tent and sleeping bags in our checked luggage, and purchased a throwaway cooler once we were out there. Most of our stays were in motels but we were able to get a last-minute campsite on the GC rim, and again near Mesa Verde. It was more about breaking up the sameness of motels than any "real" camping.

We flew round-trip ABQ, and had thought in 7 days we'd make it west to Brice/Zion. But the landscape was so fascinating, we stopped just about everywhere between Albuquerque and Flagstaff! Our circle ended up being ABQ, Sedona, Flagstaff, Wapatki Ruins/Sunset Crater Nat'l Monument, GC, 4 Corners, Durango, Mesa Verde, Great Sand Dunes NP, Taos, Santa Fe. All gorgeous: you can't really go wrong out there!

P.S. I will also vote for the car/hotel/cabin instead of the RV, regardless of which destination you choose.

As I an RV owner, I second the advice to NOT go the RV route, especially if you choose Yellowstone and the Grand Tetons. Without a towed vehicle to get around in, you'd be miserable having to use the RV to sightsee. The others do have Park transportation but your visit may fall outside of the dates when the shuttles run.

Having been to all of the Parks you're considering, it's hard to tell you which to do. A great deal depends on what you want to do once you're there. Are you into photography? Want to do some hiking - long or short? Is seeing wildlife high on your list? Your answers to those questions might tell us which option would be best.

My husband and I love Yellowstone. We've been in 3 of the seasons, lacking only spring and we hope to get to that in the next year or two. We love the geologic variety and the varied wildlife. We've been to the Tetons twice (missed it in the winter) and would gladly go back.

We were there mid-September last year and they were having a heatwave. The elk were still up in the mountains and the only the aspens at the highest elevations had begun to turn. This year, who knows? It could easily get a dusting a snow as it did in the high Tetons when were there the second week of August several years ago. That same trip we had to scrape heavy frost/ice off the windshield one morning in Yellowstone. By mid-day we were back in shorts and t-shirts.

The Grand Canyon, Zion and Bryce are so different from one another that's you'd get a good feel for the amazing variety of geology of our gorgeous Southwest. Of the 3, I don't have a favorite because they're just so different.

You can't go wrong with either trip. If I were you the first thing I'd do is go to nps.gov and see what the closing dates are for Yellowstone lodging. If lodging is going to be an issue, your destination may resolve itself.

Wherever you decide to go, you need to begin working on reservations, especially for in-Park lodging. We prefer to stay in the Parks when we can and find that to be more important some places than others. Yellowstone (especially for the lower half of the Park) and Grand Canyon are 2 that I would say in-Park really makes a difference. Bryce, almost as much because of the ease of walking out to the rim for sunrise or sunset. If everything is booked, just keep calling. People make reservations far in advance and have no penalty for cancelling if they do so in time. Ask the person you speak to what time of day might be best for trying to snag one of those cancellations.

Awesome advise guys. It sounds like renting the car is our best bet, my wife will be happy with that decision. I think the GC trip may be the wiser decision. It looks like the weather that time of year in that area may be more predictable. Should I fly into Vegas? No that we narrowed it down to GC grand circle trip. Any specific places to stay in the parks? Thanks again everyone. Steve

One other thing. What shouldn't we miss in the parks?

Vegas would be a bit closer than Phoenix but you should check airfare and rental car prices and base your decision on that. Flying into Phoenix would add a few hours of driving but if it's significantly cheaper (unlikely) then it makes sense to fly into there.

Staying inside the park is best, there's only one option for Bryce and Zion in the park. Multiple options for Grand Canyon, really depends on how much you want to spend and what's available for your dates.

My family (also from MA) visited Bryce, Zion, the Grand Canyon (north rim) and several other parks/monuments on a three week trip several years ago.

I have not visited Yellowstone or Grand Tetons. (They're on my list!)

We flew in and out of Las Vegas and rented a Jeep for our park circuit. The Jeep allowed us to do some back country driving, although it isn't a must; several of the parks offer back country tours in park/tour operated vehicles.

I highly recommend Zion and Bryce; we did ranger led hikes in both parks which we found extremely beautiful and fascinating. I don't know if these activities have survived budget cuts but, at the time we visited, there were daily offerings at all national parks and it was possible to check online for information.

We visited the Canyon's north rim for an afternoon. We were not prepared to hike into the Canyon and decided a quick peek would suffice. In place of a Grand Canyon hike, we visited a smaller more accessible canyon, Canyon de Chelly in Chinle AZ. It's possible to hike in and out in several hours and there is much to learn about the culture and history of the Navajo. Also in the area (generally speaking) is Monument Valley.

We also visited Arches (Moab UT), another gorgeous park, which is a must see in my opinion, although time and resources are of course the determinants of any itinerary.

We drove a loop starting in Las Vegas, up through Utah, down into Arizona, and returning to Las Vegas (toured the Hoover Dam on our way back).

I will acknowledge it's a great deal of driving for three weeks, but we had a wonderful trip.

Your ten days would work well for Zion, Bryce, and one other park visit, perhaps two if the driving distances (and your tolerance level for driving) permit.

I don't have any lodging recommendations; we traveled in the summer and had booked the previous winter at motels in close proximity to the parks, not in the parks (frugal travelers). None stands out for quality nor awfulness. I recall we stayed mostly at Holiday Inn/Best Western type accommodations. We are early risers and didn't have any difficulty with short drives to the parks to get an early start on the day's hiking. But, many prefer to stay within the parks; and it is less wearing on your day-to-day experience. (We stayed in a rental home in Yosemite for a week on a recent CA tour.)

Enjoy your travels whichever parks you decide to visit!

Great advice above.

My two cents: (1) Ten days is a good amount of time for seeing a bunch of parks in Utah/Arizona, but more than you need for Yellowstone and GTNP. (2) The weather will be pretty wintery at Yellowstone, but really nice in Utah/Arizona. (3)At this late date, you'll have better luck booking good lodging in Utah/Arizona. You probably won't get into the Bryce or Zion lodges, but staying outside of the parks is not a big problem at either place. So all in all, I definitely vote for Utah/Arizona.

If you do that, I'd encourage you not to think of your trip as a "Grand Canyon trip" with the other parks added on. In my opinion, the Grand Canyon is vastly overrated. I enjoyed the North Rim, but I don't think it's worth more than maybe two days at most, unless you're going to hike down to the bottom of the canyon or something. I thought the South Rim was pretty unpleasant, because of all the crowds and traffic jams - sometimes it was actually difficult to get out of a parking lot, or find something to eat. I wouldn't go back to the South Rim, and I'd recommend to anyone going there to do it as no more than a drive-by visit to the various viewpoints, without staying the night.

With ten days, I'd recommend that you see all five Utah National Parks (Canyonlands is my personal favorite, but I'm probably in the minority), and throw in a side trip to the North Rim of the Grand Canyon if you haven't seen it before.

Just a comment on hawksbill post: it is actually far better to stay overnight at the Grand Canyon instead of doing a quick drive-by during the day. The vast hordes of day visitors are what make the South Rim so crowded and unpleasant, once they leave it is quieter. Still busy, yes, but not nearly as hectic.

Grand Canyon is best experienced at sunset and sunrise. It is magical then. Plan to stay overnight.

Good point, the South Rim is much less crowded early in the day and late in the day, and the light is more interesting too. I'll revise my recommendation: the best thing would be to skip the South Rim entirely and visit the North Rim. But if you have to do the South Rim, do it as a drive-by, close to sunrise or sunset, without staying over.

Thanks for all the great comments. My wife and I will make our decision soon. Any other tidbits that you didn't mention don't hesitate to chime in again. I'll let you know how we make out.

Also, what are peoples opinion on the donkey rides through the canyon? Is it worth the sore butt for a week?

Be sure to purchase an Annual Pass! It costs $80 and is good for all people in the vehicle. It pays for itself if you visit at least 3 parks (@ $25 per park entrance fee), but it is good for one year. You can purchase them online, OR you can just wait until you get to the park and purchase from the ranger at the entrance.

Here's a link:

http://www.nps.gov/findapark/passes.htm