Mesa Verde: Cliff Dwellings of the Anasazi	The Mesa Verde archaeological region located in the American Southwest was the home of a pueblo people who during the 13th century A.D. constructed entire villages in the sides of cliffs.	Mesa Verde is Spanish for  œgreen table  and the people who lived there are often called the  œAnasazi  a Navajo word that has been translated as  œthe ancient ones  or  œenemy ancestors.  While they did not develop a writing system they left behind rich archaeological remains that along with oral stories passed down through the ages have allowed researchers to reconstruct their past.	The region they lived in is defined by researchers at the Crow Canyon Archaeological Center. It encompassed almost 10000 square miles (26000 square km) of territory going across the states of Utah Colorado and New Mexico with part of the region in Colorado forming Mesa Verde National Park.    	It was a tough place to make a living.  œCold snowy winters give way to hot dry summers and periods of relatively abundant moisture are punctuated by sporadic  � but sometimes prolonged  � periods of drought  writes a team of Crow Canyon researchers in a 2011 online article.  œLiving off the land has always been and continues to be a challenge but one that people through the ages have met with extraordinary ingenuity and resilience. 	The Crow Canyon researchers note that after A.D. 500 a people whom archaeologists refer to as the  œBasketmakers  (named from their finely woven baskets) moved from the peripheries of the Mesa Verde archaeological area into the center. They grew corn squash and beans supplementing these crops by hunting game and collecting wild plants.	In the time after they moved into the center of Mesa Verde they developed pottery and the bow and arrow. The adoption of the bow appears to have increased their hunting proficiency resulting in some game animals like deer eventually becoming overhunted and replaced with domesticated turkey.	They lived in simple pit houses with a hearth fire hole and room for storage. Entered through the roof by way of a ladder the fact that the house was partly underground helped keep it cool in the summer and warm in the winter.	These people came together in what we call  œgreat kivas  which were also located partly underground.  œThese very large (more than 100 square meters or 1076 square feet) round structures are thought to have been used for public gatherings during which members of the community socialized performed ceremonies or discussed issues important to the group  the Crow Canyon researchers write.	This way of life appears to have been quite successful at least for a time. A team of researchers report in a 2007 American Antiquity article that a portion of the Mesa Verde region located in Colorado more than doubled in population between roughly A.D. 700 and 850.	At this time larger communities began to appear in Mesa Verde that used a new type of above-ground structure known to archaeologists as  œroom blocks.  Built in addition to pit houses they contained fire hearths and places for storage. Crow Canyon archaeologists note that these room blocks were made of adobe stone and plant materials with stone masonry becoming more important as time went on.	But just as the population peaked something happened and the people left in droves. The researchers in the American Antiquity articlenote that the area of land they re studying in Colorado saw its population rapidly shrink between A.D. 850 and 930 to a level not much above zero. This appears to have happened across the Mesa Verde region with the population moving south to places like Chaco Canyon in New Mexico.	Recent research suggests that a change in climate played a role in this emigration. In a 2008 American Scientist article researchers note that pollen remains indicate that the weather in at least part of the Mesa Verde region became colder.	 œPresumably the most productive portions of this area became cold enough in the 900s to make maize (farming) risky. Dry winters compounded this problem. 	This downturn in the climate did not last and after A.D. 930 evidence indicates that people moved back into the Mesa Verde region.	Their time at sites like Chaco Canyon to the south influenced them and they brought back a type of building which archaeologists call a  œgreat house.  These functioned as community centers of sorts that stood on high ground and contained multistory rooms.	The Crow Canyon Archaeological Center archaeologists note that  œlike great kivas great houses were public structures probably used for community-wide ceremonies and meetings  they write.  œIn addition great houses  � with their large storage capacity  � may have served as central storage and distribution facilities for both food and trade items. 	Another thing the people appear to have brought from their time outside Mesa Verde was connections to a vast trade network.  œThe presence of Chaco-style pottery vessels macaw-feather sashes and copper bells at some sites indicates that the Pueblo people of the Mesa Verde region were part of a vast trading network that included not only Chaco Canyon but much more distant locations in Mexico as well  write the Crow Canyon archaeologists.	The researchers who wrote the American Antiquity article note that the population in their study area continued to grow almost continuously after A.D. 930 spiking in the 13th century. It was during this last century that people began creating what are called  œcliff dwellings  which are houses and in some cases entire villages built into cliff edges. The National Park Service estimates that there are about 600 of these preserved at Mesa Verde National Park. Built near springs the naturally enclosed sites offered protection against both the elements and intruders.	 œMany of the cliff dwellings at Mesa Verde are small only one or two rooms built in alcoves or shallow caves  writes archaeologist Larry Nordby in a chapter of the book The Conservation of Decorated Surfaces on Earthen Architecture (J. Paul Getty Trust 2006). He notes that one of the largest cliff-dwelling sites is a place we call  œCliff Palace.  It contains about 150 rooms and nearly two dozen kivas that were used presumably as a gathering place for rituals.	Cliff Palace also had many decorations that are not well preserved.  œFairly typical examples of embellishments are a panel of numerous stamped handprints above doorways and a series of zoomorphic (animal) figures painted onto plasters  Nordby writes.	The cliff settlements were not to last. Another population collapse occurred this time at the end of the 13th century leaving sites like Cliff Palace abandoned and falling into ruin. The people appear to have migrated south again to sites in Arizona and New Mexico.	Why this second and very dramatic collapse in population occurred is a mystery. In the American Scientist article researchers note that a mix of factors seems to be involved.  œA combination of factors  � including climate change population growth competition for resources and conflict  � seem to have sparked the move  they write.	At one Mesa Verde site called  œSand Canyon  people late in the 13th century were depending more on wild plants and were eating less domesticated turkey. With the population shrinking the site fell into ruin and  œrefuse was being deposited in once-important civic or ceremonial structures such as the great kiva  the researchers write.	There were also signs of a battle.  œExcavators found 23 complete or fairly complete human bodies as well as scattered bones from at least 11 other individuals indicating that at least 34 people died at or near the end of the village occupation  the researchers write noting that  œnone of these bodies was formally buried and at least eight exhibit direct evidence of violent death. 	The people who left Sand Canyon before the final fall likely joined the other people of the Mesa Verde region in migrating south to new lands.	 � Owen Jarus LiveScience Contributor	Related: