U.S. Route 81
The route of US 81 follows that of the old Meridian Highway which dates back as early as 1911. The highway has alternately (and unofficially) been known as part of the Pan-American Highway. In the part in the state of Oklahoma, the highway closely follows the old Chisholm Trail for cattle drives from Texas to railheads in Kansas in the 1860s and 1870s.