Planning National Parks Trip West - Summer 2011

Hi, first I just wanted to say that this website is great! Tons of helpful information. I'm completely new to Raods Trips and to touring the National Parks. I live in the Boston area and am planning to take a 17 day trip out West to visit several of the National Parks in the summer of 2011 and wanted to ask for some feedback on my itinerary as a sanity check. There will be two family's traveling together so there will be four adults to share the driving. Any thoughts/feedback would be greatly appreciated.

Friday - Fly out to San Francisco area, stay in the SanFran area for two nights (Friday and Saturday)
Saturday - Pick up RV Rental in SanFran area.
Sunday- Leave for Yosemite National Park. This is approximately a 5 hour drive from the SanFran area.
Camp at Yosemite National Park for three nights (Sunday, Monday, Tuesday)
Wednesday - Travel to Yellowstone National Park. This is approximately a 14 hour drive which could be broken up with a stop overnight someplace along the way.
Camp at Yellowstone for 4 nights (Wednesday, Thursday, Friday, Saturday)
Sunday - Travel to Zion National Park in Utah. This is approximately an 11 hour drive.
Camp at the Zion National Park/Bryce Canyon National Park area for three nights (Sunday, Monday, Tuesday)
Wednesday - Travel to Grand Canyon National Park In Arizona on Wednesday. This is approximately a 6 hours drive.
Stay in Grand Canyon National Park for two nights (Wednesday, Thursday)
Travel back to the San Fran area on Friday. This is approximately 12 hours.
Stay in the SanFran area for two nights (Friday, Saturday)
Drop off RV on Saturday
Fly home on Sunday

The times I used were from Yahoo Maps and are approximations.

Thanks,
Michael

Hello and welcome to the RTA forums !

You have the time to make your trip work but there is no way will you get from Yosemite to Yellowstone in 14 hours, in an RV I would estimate it to be a minimum of 2 x 10//11 days, so an overnight stop will most certainly be required.
The same would apply for your journey to Zion as the mapping times do not allow for food, bathroom, fuel breaks, traffic congestion or the fact you are in an RV. I would allow 13 hours for this trip and plan on spending the night 2 or 3 hours away from the park. And, you guessed it, GC to SF in an RV would be nearer to 15 hours + than 12 and you might want to consider stopping on route.