There are two routes along the Mississippi. One is right on the river. It is full of short, steep, abrupt hills, and can be very difficult. The other is farther west and away from the river banks and not nearly as hilly. I got caught out in some really bad weather, and spent the night in the number 1 fire department in Minneapolis when the worst storm since the early 1800s blew through. It killed people and leveled communities.
There is a lot of very beautiful scenery across the northern tier. There are Glacier National Park, the Going to the Sun Highway, and Logan Pass at the continental divide all in one strip. There is a station at the top of Logan Pass. I got there at night, so it was closed.