Four Corners Monument
The Four Corners Monument marks the quadripoint in the Southwestern United States where the states of Arizona, Colorado, New Mexico, and Utah meet. It is the only point in the United States shared by four states, leading to the area being named the Four Corners region. The monument also marks the boundary between two semi-autonomous Native American governments, the Navajo Nation, which maintains the monument as a tourist attraction, and the Ute Mountain Ute Tribe Reservation.
Colorado
Colorado is notable for its diverse geography, which includes alpine mountains, high plains, deserts with huge sand dunes, and deep canyons. In 1861, the United States Congress defined the boundaries of the new Territory of Colorado exclusively by lines of latitude and longitude, stretching from 37°N to 41°N latitude, and from 102°02'48"W to 109°02'48"W longitude (25°W to 32°W from the Washington Meridian). After years of government surveys, the borders of Colorado are now officially defined by 697 boundary markers and 697 straight boundary lines. Colorado, Wyoming and Utah are the only states that have their borders defined solely by straight boundary lines with no natural features. The southwest corner of Colorado is the Four Corners Monument at 36°59'56"N, 109°2'43"W. This is the only place in the United States where four states meet: Colorado, New Mexico, Arizona, and Utah.