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 .
Four Corners, Oregon
Four Corners is a census-designated place (CDP) in Marion County, Oregon, United States, just outside the city limits of Salem but within the city's urban growth boundary. It is part of the Salem Metropolitan Statistical Area. The population of the CDP was 13,922 at the 2000 census. It is named after the intersection of State Street and Lancaster Drive.