New Mexico is a state in the southwestern region of the United States of America. Over its relatively long history it has also been occupied by Native American populations and has been part of the Imperial Spanish viceroyalty of New Spain, part of Mexico, and a U.S. territory. Among U.S. states, New Mexico has simultaneously the highest percentage of Hispanic Americans (comprised of both recent immigrants and descendants of Spanish colonists) and the second-highest percentage of Native Americans after Alaska (mostly Navajo and Pueblo peoples). As a result, the demographics and culture of the state are unique for their strong Spanish, Mexican, and American Indian cultural influences. The climate of the state is highly arid and its territory is mostly covered by mountains and desert. At a population density of 15 per square mile, New Mexico is the sixth most sparsely inhabited U.S. State.