Numbered Highways created in 1926 by the American Association of StateHighway Officials. The route of US 81 follows that of the old Meridian Highway which
Primary Interstate Highways are the major interstate highways of the United States and have a one or two-digit route number. Even (0, 2, 4, 6, or 8) route
follows the Santa Fe Trail. The highway goes through New Mexico, Oklahoma, Kansas, and Missouri. It also touches a corner of Texas at a small road junction near