Dune Dam is a long sand dune that lies at the western end of

Chaco Canyon Chaco Culture National Historical Park is a United States National Historical Park in the American Southwest hosting a concentration of pueblos. The park is located in northwestern New Mexico, between Albuquerque and Farmington, in a remote c ...

, New Mexico, near the confluence of the Chaco and Escavada Washs. The dune was created by winds that brought sand up the Chaco River. When the dune was large enough, it dammed the Chaco Wash and created a small and shallow lake near the

Ancestral Puebloan The Ancestral Puebloans, also known as the Anasazi, were an ancient Native American culture that spanned the present-day Four Corners region of the United States, comprising southeastern Utah, northeastern Arizona, northwestern New Mexico, an ...

great house A great house is a large house or mansion with luxurious appointments and great retinues of indoor and outdoor staff. The term is used mainly historically, especially of properties at the turn of the 20th century, i.e., the late Victorian or ...

, Penasco Blanco. Archeological evidence suggests that the dune was breached around 900 CE. Chacoans filled the breach with masonry sometime in the early 11th century, and built an accompanying reservoir lined with stones that was visible until 1920. The dam stopped Chaco Wash from further deepening, which helped raise the water table in the canyon, aiding Chacoan farming. The absence of a

lacustrine plain A lacustrine plain or lake plain is a plain formed due to the past existence of a lake and its accompanying sediment accumulation. Lacustrine plains can be formed through one of three major mechanisms: glacial drainage, differential uplift, and inla ...

behind the dam led geologist Stephen A. Hall to question this interpretation.

References

;Bibliography * {{authority control Archaeological sites in New Mexico Chaco Canyon Chaco Culture National Historical Park Colorado Plateau Ancestral Puebloans Post-Archaic period in North America Native American history of New Mexico