New Mexico
1. Chaco Canyon National Monument (1907), was re-designated Chaco Culture National Historical Park (1980) - it is also a UNESCO World Heritage Site (1987). The park is located in northwestern New Mexico, in a remote canyon formed by the Chaco Wash. It lies in the San Juan Basin, in the southeast corner of the Colorado Plateau. This park contains the the densest collection of ancient ruins (pueblos) north of Mexico, and preserves one of the United States' most important precolumbian cultural and historic areas. Between AD 850 and 1250, Chaco Canyon was a major center of culture for the ancient Pueblo Peoples, also called Anasazi. Chacoans quarried sandstone blocks and hauled timber from great distances, assembling fifteen major complexes which remained the largest buildings in North America until the 19th century. The park's vegetation is predominantly Great Basin grassland and desert scrub. Riparian vegetation, including cottonwood and willow groves, are locally abundant along the arroyo within the canyon floor. Three prominent land forms: (1) the alluvium-filled valley floor of Chaco Canyon, with its prominent drainage features; (2) expansive Cretaceous sandstone mesas, topped by slickrock outcrops and gently rolling hills; and, (3) a number of small side canyons (locally known as "rincons") eroded into the sandstone faces adjacent to the main canyon floor.
2. Gila Cliff Dwelling National Monument (1907) - located in New Mexico, within the Gila National Wilderness Area (1924), the first wilderness area to be established in the United States. The cliff contains the ruins of interlinked cave dwellings built in five cliff alcoves by the Mogollon people whose culture lived in these cliff dwellings from between 1275 and 1300 AD, which is the only location that contains Mogollon sites. In the immediate vicinity of the Cliff Dwellings, elevations range from 5,700 to about 6,000 feet. The terrain is rugged, with steep-sided canyons cut by shallow rivers and forested with ponderosa pine, Gambel's oak, Douglas fir, New Mexico juniper, pinon pine, and alligator juniper
Read More2. Gila Cliff Dwelling National Monument (1907) - located in New Mexico, within the Gila National Wilderness Area (1924), the first wilderness area to be established in the United States. The cliff contains the ruins of interlinked cave dwellings built in five cliff alcoves by the Mogollon people whose culture lived in these cliff dwellings from between 1275 and 1300 AD, which is the only location that contains Mogollon sites. In the immediate vicinity of the Cliff Dwellings, elevations range from 5,700 to about 6,000 feet. The terrain is rugged, with steep-sided canyons cut by shallow rivers and forested with ponderosa pine, Gambel's oak, Douglas fir, New Mexico juniper, pinon pine, and alligator juniper