Indy to Yosemite and Back

My family of 2 adults and 4 kids (ages 14 to 6) is planning a road trip from Indianapolis to Yosemite (a family reunion) in July 2004. We have three weeks to make the trip. Spending a minimum four days in Yosemite.
I'm looking for sites along the way, tips on camping enroute and an idea of what route(s) would be best.
The current plan has us driving through St. Louis, OK city, Amarillo and Flagstaff to Yosemite. I'd like to take a different route back...maybe 70E through Salt Lake City, Cheyenne, Nebraska and Iowa back to Indy.
We have a chance to use a friend's apartment in Phoenix. Is that close enough to the Grand Canyon or should we stay closer? I want to see Hoover Dam...what's the best route to Yosemite from there? Through Death Valley (IN JULY!!!) or south toward LA?
I'm open to any and all suggestions...I want to see the world's biggest ball of string! Help me people!

Coming in on I-40 is a nice drive. Watch for Cadallic Ranch just west of Amarillo. There are 10 old caddy's that have been buried with their tail fins sticking straight up in the air. Petroglyphs National Monument just outside of Alburquerque. Painted Desert & Petrified Forest just east of Holbrook, AZ. You can go stand on the famous Eagles corner in Winslow, AZ. Walnut Canyon National Monument just east of Flagstaff.

It is 230 miles from Phoenix to the Grand Canyon and I wouldn't do the drive as a day trip. I would make reservations to camp at the Mather Campground at the S. Rim of the Grand Canyon and then you will have a parking spot and can ride the shuttle buses almost everywhere you need to go. I would come in on Hwy 89 and do Hwy 395 loop to Sunset Crater and Wupatki National Monument and enter the Grand Canyon at Desert View entrance and stop along the way at the scenic overlooks to the Grand Canyon Village.

There are several options from driving from Las Vegas to Yosemite. Death Valley is going to be HOT but that's an option and then drive up Hwy 395 and enter Yosemite at Lee Vining. There are national forest campgrounds as you start driving up Hwy 120 towards Yosemite from Hwy 395. We've found these primitive campgrounds do not fill up even in the summer. This might be a place to camp before entering Yosemite. You will need to make reservations in Yosemite months in advance if you want to camp in Yosemite Valley in July.

If you want to avoid Death Valley then from Las Vegas take Hwy 95 to Tonopah, NV and then take Hwy 6 to Hwy 120 at Benton, CA. This drive across 120 is really scenic.

I-80 between Salt Lake City and Cheyenne is very BORING!!!! The first part thought the mountains after Salt Lake City is nice but then you have 400 miles of one light brown hill after another.

I would take Hwy 50 across Nevada and then pick up I-70 in Utah. There are many interesting sites on Hwy 50. Petroglyphs, old pony express stations & sand dunes and near by is Great Basin National Park. On I-70 in Utah you will drive thought the scenic San Rafael Swell between Fremont Jct. & Green River. They are trying to make this a National Monument. If you find you have some time I would drive down to Moab, Utah and explore Arches National Park. From Moab, UT drive out Hwy 128 and connect up with I-70 again. Hwy 128 is a very scenic drive along the Colorado River with high sheer red sandstone walls on both sides of you.

I-70 in Colorado is very scenic and you can take a little detour thought Colorado National Monument and you could also drive thought Rocky Mountain National Park. Unless you have a really great desire to go to Cheyenne, it would be out of your way and I would just take I-76 up to I-80.

I'm not that familar with the east.

Utahtea

This is just the kind of info I'm looking for. I would have driven past half the places you mentioned. I was looking at the I-70 return trip...but the I-70-with-several-detours looks great. Keep 'em coming!