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Apparently the Yellowstone Trail (from Minneapolis) was established for cars in 1914. I suspect that US Hwy 212 is follows this route and for much of the way might be satisfactory for bicycling. You'd have to check out traffic levels and shoulders. There might be some cool historical places you could visit along the way.
Out west they allow you to bike on the shoulders of the expressways. That might help.
With research you probably can find a good way accross Minneapolis-St. Paul. You could also take city buses. All have bicycle racks nowadays.
There is a good Wisconsin bicycle map that could guide you from Chippewa Falls to the Twin Cities area, which would be the most direct route. Of the four available maps you'd want the Mississippi River section. You can order them from Wheel and Sprocket bike shop in Hales Corners, Wi. I don't have the phone number, though. You'd want to cross the Mississippi at Stillwater, Mn; Hudson, Wi (there is a bike bridge on Interstate 94); Prescott, Wi; Or Red Wing, Mn. From Red Wing there's a very nice Bicycle trail to Cannon Falls. There's also a nice one from Faribault, Mn to Mankato.