How many days to allow for Yellowstone.
 

This is the very beginning of my plans for our 4-5 week tour to Utah, Arizona and hopefully up to Yellowstone. My question is whether to fly from San Francisco to Salt Lake City, then drive to YNP, or drive the whole way. Is it worth driving that far to SLC.
Second Question is, how many days would we need in YNP to see it properly.
Other places we would like to visit are Moab Nat. Park, Mesa Verde, grand canyon, Bryce Canyon Nat park, Zion Nat Park, and Yosemite.
This will most likely be a once in a lifetime trip from NZ, so we don't mind doing a lot of driving.

Moab is a city, you will be visiting Arches National Park and Canyonlands National Park.

Yellowstone 3-5 days
Grand Teton 1-3 days
Grand Canyon 1 day
Bryce 1-2 days
Zion 2-3 days
Mesa Verde 2 days
Yosemite 3-5 days
Moab 2-5 days

What you plan on doing at each spot will determine how long to stay there. I would try to stay at the Historic Lodges in all the parks. In Yellowstone I would suggest staying 3 different spots
Roosevelt Lodge, Lake Hotel, and Old Faithful Inn.

Are you planning on seeing the Grand Canyon from the North Rim or South Rim?

Since you have to drive to Yosemite from San Francisco, I would continue the drive. It will be a very very boring drive. Driving back to San Francisco and flying would still cost you a long day. If you could fly from Fresno to Jackson, it would be worth the effort, but it would be much more expensive flight.

Finally, I hope this is for 2012, as it would be difficult to plan this for this year.

Buy a National Park Pass to save a lot of money on this trip.

Give Yellowstone at least two FULL days. A lot of people do the southern loop one day and the northern loop the next day. It is large and driving is slow plus there are lots of stops to make. You don't see the park from the car. You have to get out and walk to see things. They will give you a really good map when you enter the park.

Also, you need to stay in the park so make reservations months early but if they are full keep calling for cancellations. They are common. Because of the long driving distances, driving just to get into the park eats up a lot of time. If you have to stay outside the park, West Yellowstone is the most centrally located town.

Bryce Canyon, Zion and Grand Canyon can be done in one day each, unless you want to do some long distance hiking. I haven't been to Mesa Verde.

There is no Moab National Park but a town of Moab with Arches and Canyonlands National Parks nearby. I haven't spent any time here either so I can't speak about time needed. I just wanted to give you better terms to use for your research.

These are minimum days. You could certainly spend more time.

Carrentals.com roadtrip out of SF beautiful cheaper plenty to see

Fox car rental cheapest for me there usuallly

Classic.mapquest.com

Directions distances 3 days at yellowstone.com area

Utahparks.com also awesome on your way drop down to yosemite.com also great

Have fun lots of nice cheap hotels on your way betterbidding.com

Four or 5 weeks gives you a lot of time! Hopefully you can make it for the 5 weeks.

I agree with a lot of spirobulldog's times but I would do a little different time frame.

Yellowstone 5 - 6 days to properly see the park as you asked
Grand Teton 1-2 days
Grand Canyon South Rim 2 day
Bryce 1-2 days
Capitol Reef National Park 1 -2 days (drive Hwy 12 to Bryce)
Zion 2-3 days
Mesa Verde 2 days
Yosemite 3-4 days
Moab 3-5 days to see Arches & Canyonlands

Connie gave a time frame for just scratching the surface of these parks.

I like to recommend the South Rim of the Grand Canyon for first timers.

What time of the year are you planning this trip?

Utahtea

Thank you all for your excellent advice. We are planning this for September 2012 so giving ourselves plenty of time to plan.

I have read that you need to book well in advance for accom. in Nat. Parks.

Does that still apply for Sept?

Not sure about North or South Rim.Probably will depend on where we are at the time.

September is still very popular especially in the south west. Some of Yellowstone's accommodations start closing in September, so you might want to check for lodging here first. http://www.nps.gov/yell/planyourvisi...CP_JUMP_127510

You are getting an early start to planning so that is EXCELLENT!

Utahtea

You'll have a range of temperatures on the trip as well. Can be cold in the mountains and warm in the desert. Utahtea has a good plan.

We spent a week in Yellowstone- very worth the time. There is just so much to see.

We did four full days in Yellowstone, two nights in Gardner and two in West YS. That was plenty of time for us, even to explore the various geyser basins.