We live in PA and are planning a 4-6 week drive in May across the USA to visit places we've never seen before.
The following is our PRELIMINARY itinerary: (We're intentionally leaving out how much time we'll be in each place).
Pittsburgh, Cleveland, Chicago, Madison WI, (Maybe Minneapolis for MOA), Rapid City, Yellowstone NP, Bozeman MT, Glacier NP Calgary & area, Vancouver, Seattle, Portland, SF-LA via PCH, Vegas, Zion NP, Denver & Colo Sp, Kansas City, St Louis, Cinn, back to PA.
Please help us tweak this.We need suggestions on weather, sights along the way to fill in the blanks, most of all help in eliminating "same old, same old" as in "1 glacier's the same as another" etc. We DO NOT hike, camp, or fish.

Yosemite? Death Valley? Mono Lake? Grand Canyon? Zion? Bryce Canyon? Monument Valley? Canyon de Chelle? Chaco Canyon?

My only advise is that you MUST have reservations for accomodations in the popular national parks if you are going in the summer. Do not expect to roll up and find a room. They will be full, full, full.

If you can I think I would the southern tier, first then the northern on the return due to timing.

Yes, because of weather, I would do the southern more part of your loop first.

Great advice! Makes sense. I think we will do the southern tier first. We've already done most of the southwestern canyons.

I think six weeks is better than 4; also agree that the southern route westbound makes more sense, more to avoid the heat in the SW rather than good weather in the north. I too would add some additional stops in the southwest/four corners area (Canyon de Chelly, Monument Valley, Grand Canyon) - you can loop back up to Zion en route to LV pretty easily.

On the northern tier, Yellowstone and Banff NPs would be my main objectives, and heed the warnings about accommodations at Yellowstone. Try West Yellowstone for lodging rather than in the park if things look tight.

It's quite an ambitious itinerary but doable. You will need to limit your city time to some degree unless you like to tour on a drive-by basis (which is quite legitimate for some of your destinations.)

Add Mt. Rushmore. It's interesting.

Go to www.lightninrv.com and click on "Rentals" in the menu on the left (you don't have to be an RVer to use all this great travel information)...our site is designed for road trips! Once we come up, take a look at our "Special Events Calendar", again in our menu on the left, for a list of great events all over the country. But, don't look at it for just the time period you're going out, look at the entire year as the places we list are good travel sites just about all year long.

The take a look at our "Travel Links" where you'll find some very helpful sites...MapQuest of course, but also a national D.O.T. site for weather & road conditions...and a bunch more. There's some fun ones as well like "The Largest Roadside Attractions in the U.S." and "The Wackiest Tourist Attractions in the U.S." for some great things to see/do.

My family and I did a somewhat similiar trip last June for 5 weeks. We did the inside loop from NJ up to SD, MT, WY, UT, AZ, NM, CO, MO, KY, VA (20 states total)and it was fantastic. However the heat in July in the southwest was amazing. I would suggest starting on the southern route and head north. We did not camp but stayed in cabins and hotels that we book 1 year in advance.

As a result of input from folks like you, we've decided not to take my Civic with 195k miles and get a new car for what looks like an extended trip. We knew that there was so much to see/do in this great country but we continue to solicate more info. What fun!! We want time to savour the towns we visit rather than just buzz through them. It is really a once in a lifetime trip and your help is vital. Not everything is in books. I know we'll need reservations in advance for the major sites, but what about the places in between? We'd really like to stay flexable. It that possible?
Thanks again, Irv

See if you fit in Washington Olympic Peninsula...you can then take the ferry from Port Angeles to Victoria which is worth the visit and thence to Vancouver.
In California consider Yosemite of course, but also Lassen Park and the Redwoods on northern CA. If you've never been to Death Valley, take the "back" roads over there from Las Vegas. From DV you can swing south to cross the Sierra into the Central Valley or take 395 north and cross at Carson City to got through Lake Tahoe.
Sounds like a really fun trip!

When you visit Madison, Wisconsin, make sure you stop at the Univ. of Wisconsin's Student Union and grab a chair out on the terrace next to Lake Mendota. It's a gorgeous spot to catch some rays, enjoy the students, have a brat, and watch the sailboats. Madison is built on an isthmus between a couple of very large lakes, so it's lovely in the warm months.