Recently my adventures took me to Montana, LA, Anaheim, San Diego, Coronado Island and Chicago, not to mention Minnesota and North Dakota, opps. It took all of a month to enjoy and I used several modes of transportation. Car, driving to Montana takes two people and an overnight. Illinois is long like Florida or the UP right? Well try North Dakota and Montana they are very long. Anyway take as long as you can and enjoy. Glacier National Park and Lake McDonald (don't worry no Ronald) are a must, first the rock slide, then the three bears, and then the lake.
(Teddy Roosevelt National Park North Dakota)

(The west is the best side of Montana look hard

and see the mountain [below the clouds on the horizon, squint] range after about 14 hours)
Note:
Highway 2 is NOT for new drivers and it takes all of an experienced drivers skills this highway is covered with crosses marking traffic fatalities, hundreds and hundreds of them.
Highlights:
Saw a herd of buffalo in Minnesota, which should be called land of a thousand ponds as the lakes are a bit small. Outside of a few hours in Illinois and Minnesota everything was pretty flat until...

Lake McDonald and the Little Alps From the back of the Red Bus

I took Amtrak's Empire Builder home which was something I always wanted to do. Great Trip! If you like to strech your legs meet people and get a bit of shut eye. I will say however the biggest downside was the conditions of the bathrooms! Bad NEWS! Someone should be responsible to keep them up! I'd volunteer if I got paid a million dollars. Oh, I rode coach as I was on a budget and no what? I usually can't sleep on the train anyway not even in the Sleeper butt, I'm sure my toilet would have been clean. Well this trip lived up to my expectation though Amtrak certainly missed an opportunity to insure that I would be back! Missed the marketing boat Amtrak!
Spent most of the time in the observation car which, by the way is not like the old Vista Domes too bad they were nicer. Later after Montana my trip on The Surfliner from Anaheim to Dan Diego was fun and enjoyable.