Quadripoint
The Four Corners Monument is the only point in the United States where four states meet: Colorado, Utah, New Mexico, and Arizona meet at right angles. The United States first acquired the area now called Four Corners from Mexico after the Mexican–American War in 1848. In 1863 Congress created Arizona Territory from the western part of New Mexico Territory. The boundary was defined as a line running due south from the southwest corner of Colorado Territory, which had been created in 1861. By defining one boundary as starting at the corner of another Congress ensured the eventual creation of four states meeting at a point, regardless of the inevitable errors of boundary surveying. The monument is centered at .
U.S. Route 64 in Oklahoma
U.S. Route 64 (US-64) is a U.S. highway running from the Four Corners area to the Outer Banks of North Carolina. Between these two points, the highway passes through the entire width of Oklahoma; a total of of US-64 lies in the state of Oklahoma. US-64 enters the state from New Mexico, crossing the line between the two states between Clayton, New Mexico, and Boise City in Cimarron County. The route runs the full length of the Oklahoma Panhandle, then serves the northernmost tier of counties in the main body of the state before dipping southeastward to Tulsa, the state's second-largest city. From Tulsa, the highway continues southeast, leaving Oklahoma just west of Fort Smith, Arkansas. In addition to Tulsa, US-64 serves fifteen Oklahoma counties and the cities of Guymon, Woodward, Enid, and Muskogee.