[Ladybugsmom]

I think you should take either I80 or I90 to Yellowstone, then after visiting there (you'll need at LEAST a couple of days) head north to Glacier (mostly on US 89), then after a few days there, take US 2 through Idaho (a stop in Couer D'Alene would be nice) and Washington (a detour up to HWY 20 to cross the mountains is a very good idea). After visiting Washington (drop me a line, if I have the day off, I'll be happy to show you around!) be sure to take a side trip to see Mount St. Helens on your way south. The 32nd anniversary of her eruption was on May 18th, and I hear they have some new displays at the visitor center. A nice overnight or longer stop on your way south, on the Oregon Coast is Cannon Beach. If you go 101 all the way south, it's going to make the trip a LOT longer. You could go I5 through OR, then cut over to 101 through northern CA the rest of the way to Petaluma.