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 .
List of the major 100-kilometer summits of the United States
Of these 107 major 100-kilometer summits of the United States, 38 are located in Alaska, nine in California, eight in Montana, seven in Arizona, six in Nevada, four in Hawaii, four in Wyoming, four in Utah, three in Washington, three in Colorado, three in New Mexico, three in Idaho, three in Oregon, two in North Carolina, two in Maine, two in New York, two in Texas, and one each in New Hampshire, Arkansas, West Virginia, South Dakota, and Tennessee. Two of these summits lie on the international Alaska-British Columbia border and one lies on the Tennessee-North Carolina state border.