Driving to Cali

[gargamel]

For the desert part of the trip, if you aren't in a rush, I'd consider driving to the southern part of the Grand Canyon, going through Monument Valley then north through Moab. It will probably add 10 hours of driving time to your trip and more than that in sightseeing time, but it's worth it if you have the time to spare.

[Gugstanley]

My vote goes in for doing both routes if you havent done them before. Going down the west coast is a must see but not if you are in a hurry. You will get frustrated. Lots of places to stop and get the kids out of the car for a bit.
The other route is a lot faster. If you are nice I might let you stop at my place for dinner.

[Redliner]

I have never done the coastal route, but the I-15 route isn't as bad as some are making it out to be. Montana has some very pretty stretches between Great Falls & Helena, and again between Helena and Butte. The Monida Pass is kind of a wasteland, and unless you are into lava rock I can't think of anything really spectacular along the I-15 in Idaho. Utah, especially southern Utah, is very nice if you like desert scenery. Check out Kolob Canyon near Cedar City, Bryce Canyon, and Lake Powell. St George is nice, and the Virgin River section of Arizona is one of the most spectacularly-engineered sections of highway I think I have seen anywhere. Vegas is......well, Vegas. I'm sure you'll find lots to see no matter which way you decide to go.

[MRCboicgy]

Yah, I have 10-12 days to do a roadie in August. I've heard that Yosemite is "dried up" by then. I don't know if I should hold off going down that way until I can get time off in June instead. I have done from San Fran to San Diego on the coast---it's really nice