Mesa Verde National Park is a national park of the United States and UNESCO World Heritage Site located in Montezuma County, Colorado, and the only World Heritage Site in Colorado. The park protects some of the best-preserved Ancestral Puebloan ancestral sites in the United States. Established by Congress and President Theodore Roosevelt in 1906, the park occupies 52,485 acres (212 km) near the Four Corners region of the American Southwest.
Settlements change over centuries
The Pueblo II Period is marked by the growth and outreach of communities centered around the great houses of Chaco Canyon. Despite their participation in the vast Chacoan system, Puebloan retained a distinct cultural identity while melding regional innovation with ancient tradition, inspiring further architectural advancements; the 9th century Puebloan pueblos influenced two hundred years of Chacoan great house construction. Droughts during the late 9th century rendered Ancestral Pueblo people's dry land farming unreliable, which led to their growing crops only near drainages for the next 150 years. Crop yields returned to healthy levels by the early 11th century. By 1050 the population of the area began to rebound; as agricultural prosperity increased, people immigrated to Mesa Verde from the south.
A severe drought from 1130 to 1180 led to rapid depopulation in many parts of the San Juan Basin, particularly at Chaco Canyon. As the extensive Chacoan system collapsed, people increasingly migrated to Mesa Verde, causing major population growth in the area. This led to much larger settlements of six to eight hundred people, which reduced mobility for the Puebloans, who had in the past frequently relocated their dwellings and fields as part of their agriculture strategy. In order to sustain these larger populations, they dedicated more and more of their labor to farming.
Architecture in the cliffs
Mesa Verde is best known for a large number of well-preserved cliff dwellings, houses built in alcoves, or rock overhangs along the canyon walls. The structures contained within these alcoves were mostly blocks of hard sandstone, held together and plastered with adobe mortar. Specific constructions had many similarities but were generally unique in form due to the individual topography of different alcoves along the canyon walls.
In marked contrast to earlier constructions and villages on top of the mesas, the cliff dwellings of Mesa Verde reflected a region-wide trend towards the aggregation of growing regional populations into close, highly defensible quarters during the 13th century. This multi-storied ruin, the best-known cliff dwelling in Mesa Verde, is located in the largest alcove in the center of the Great Mesa. It was south- and southwest-facing, providing greater warmth from the sun in the winter. Dating back more than 700 years, the dwelling is constructed of sandstone, wooden beams, and mortar.
Many of the rooms were brightly painted. Cliff Palace was home to approximately 125 people, but was likely an important part of a larger community of sixty nearby pueblos, which housed a combined six hundred or more people. Balcony House is set on a high ledge facing east. Its 45 rooms and two kivas would have been cold during the winter. Visitors on ranger-guided tours enter by climbing a 32 ft (10 m) ladder and crawling through a small 12 ft (4 m) tunnel.
Migration and survival
The Mesa Verde region saw unusually cold and dry conditions during the beginning of the 13th century. This might have driven emigration to Mesa Verde from less hospitable locations. The added population stressed the mesa's environment, further straining an agricultural society that was suffering from drought. The region's bimodal precipitation pattern, which brought rainfall during spring and summer and snowfall during autumn and winter, began to fail post-1250. After 1260, there was a rapid depopulation of Mesa Verde, as "tens of thousands of people" emigrated or died from starvation.
Many smaller communities in the Four Corners region were also abandoned during this period. The Ancestral Puebloans had a long history of migration in the face of environmental instability, but the depopulation of Mesa Verde at the end of the 13th century was different in that the region was almost completely emptied, and no descendants returned to build permanent settlements. Starting in the 6th century, the farmers living in central Mesa Verde cultivated corn, beans, squash, and gourds. The combination of corn and beans provided the Puebloans with the amino acids of a complete protein.
When conditions were good, 3 or 4 acres (12,000 or 16,000 m) of land would provide enough food for a family of three or four individuals for one year, providing they supplemented with game and wild plants. As Puebloans increasingly relied on corn as a dietary staple, the success or failure of crop yields factored heavily into their lives.