New Mexico is a state located in the southwest and western regions of the United States. New Mexico is also usually considered one of the Mountain States. New Mexico is the 5th most extensive, the 36th most populous, and the 6th least densely populated of the 50 United States. Inhabited by Indigenous peoples of the Americas for many centuries, New Mexico has also been part of the Imperial Spanish viceroyalty of New Spain, part of Mexico, and a U.S. territory. Among U.S.