Will be heading to Michigan from Colorado in late June. Would rather not super slab it most of the way. Any route suggestions would be appreciated. (Round Trip BTW)
With all due respect to those that live in between Colorado and Michigan. Have you considered flying.
I could be wrong, and for your sake I hope I am. Hopefully someone local to those states will come along and
show us some interesting routing. Faced with your task (are you sure you can't get out of it?) I would just let Google maps come up with the
fastest slab routing and then zoom in and find the most parallel non-interstates and drag the route over to them.
If you get lucky and have more than one alternate choice just drag the little google man to each and compare the street views.
Northern Wisconsin is nice (not as nice as Colorado), but I'm sure that if you were headed for the Michigan U. P. you would have mentioned it. Right?
Good Luck!