Each travel season I plan a theme for our travels as we travel from South (Mexico) to the North (Washington state).  We aren't looking for a direct route, we like to wander as we go.  We have done the Pacific coast (lighthouses), Highway 395 (ghost towns) Colorado/New Mexico (ancient Indian ruins), Utah (Big 5 National Parks), East Coast loop (Washington DC).

We've now done 8 different routes to get back to our domicile state.  This year we are headed toward Saskatchewan, Canada to visit friends before heading to Washington.

We don't want to rush getting there because of weather concerns.  

Any suggestions for sites to see between Tucson and Saskatoon or maybe from Saskatoon to Tacoma?

What do you like to do? Assume you have done both sides of the Grand Canyon? Have you done part of the Lewis & Clark trail? You can pick that up near St. Louis going north into the Dakotas. Eisenhower family home in Abilene, Kansas. Bridges of Madison County in Iowa, "Field of Dreams" baseball site in Iowa, Pipestone National Monument in Minnesota just east of Sioux Falls, SD.