Salinas Pueblo Missions National Monument, in central New Mexico, is a 446-ha (1,101-acre) region containing three pueblo ruins of Native American Indians who abandoned the area in the late 17th century, as well as four of the six 17th-century Spanish Franciscan mission churches that survive in the United States. Each pueblo site contains groupings of apartmentlike dwellings made of stone and adobe. The sites, known as Abo, Quarai, and Gran Quivira, are a mixture of two ancient southwestern cultural traditions, the Anasazi and the Mogollon, who had settled in separate areas of the region as early as a.d. 800. Over the centuries the cultures mixed and the Salinas Valley became a major trade center, with about 10,000 or more inhabitants. The Spanish missionaries called the settlement Pueblo de las Humanas. Thousands of 17th-century Indian and Spanish artifacts have been found in the Salinas Valley. First proclaimed as a (smaller) national monument in 1909, the site has been enlarged several times; its current name was bestowed in 1988.