U.S. 61
Maybe someone in Duluth should play Bob Dylan's "Highway 61 Revisited," because US 61 ought to go back to the Canadian border.

US 61 could multiplex with I-35 from Wyoming to Duluth, and it would also replace MN 61 from Duluth all the way to Grand Portage.  Alternatively, a new alignment could also run parallel to I-35 all the way to Duluth.  Either way, MN 61 would be redesignated as US 61.