This also makes it the longest three-digit U.S. highway. The second highway is US Highway 12 that runs east–west across northern South Dakota from the Minnesota border before curving northwest into the southwestern corner of North Dakota.
This also makes it the longest three-digit U.S. highway. The second highway is US Highway 12 that runs east–west across northern South Dakota from the Minnesota border before curving northwest into the southwestern corner of North Dakota.