Cahokia Mounds State Historic Site

Outstanding Universal Value

Brief synthesis

Located in Collinsville, Illinois near the city of St. Louis, this largest pre-Columbian settlement north of Mexico is the pre-eminent example of a cultural, religious, and economic centre of the Mississippian culture (800–1350), which extended throughout the Mississippi Valley and the south-eastern United States. This agricultural society may have had a population of 10,000–20,000 at its peak between 1050 and 1150, which was equivalent to the population of many European cities at that time. It once covered more than 1,600 hectares and included some 120 mounds.

Cahokia Mounds State Historic Site includes 51 platform, ridgetop, and conical mounds; residential, public, and specialized activity areas; and a section of reconstructed palisade, all of which together defined the limits and internal symmetry of the settlement. Dominating the community was Monks Mound, the largest prehistoric earthen structure in the New World. Constructed in fourteen stages, it covers six hectares and rises in four terraces to a height of 30 meters. The mounds served variously as construction foundations for public buildings and as funerary tumuli. There was also an astronomical observatory (“Woodhenge”), consisting of a circle of wooden posts. Extensive professional excavations have produced evidence of construction methods and the social activities of which the structures are further testimony. 

Criterion (iii): Dating from the Mississippian period (800–1350 at this site), Cahokia Mounds is the largest pre-Columbian archaeological site north of Mexico; it is also the earliest of the large Mississippian settlements. It is the pre-eminent example of a cultural, religious, and economic center of the prehistoric Mississippian cultural tradition.

Criterion (iv): Cahokia graphically demonstrates the existence of a pre-urban society in which a powerful political and economic hierarchy was responsible for the organization of labor, communal agriculture, and trade. This is reflected in the size and layout of the settlement and the nature and structure of the public and private buildings. 

Integrity

Within the boundaries of the property are located the main elements necessary to understand and express the Outstanding Universal Value of Cahokia Mounds State Historic Site, including the central mounds, the palisade, most of the “Woodhenge” and the functional areas. All three types of mounds are preserved, as well as borrow pits. The course of the palisade remains almost completely intact. Large areas adjacent to the core of the site have been acquired, reclaimed from development, and restored to preserve the historic setting. The property is thus of sufficient size to adequately ensure the complete representation of the features and processes that convey the property’s significance, and it does not suffer from adverse effects of development and/or neglect. Although there is no official buffer zone, designation by the federal government of a larger area as a National Historic Landmark (1964), now containing additional State-owned property, provides equivalent protection. 

Authenticity

Cahokia Mounds State Historic Site is authentic in terms of its forms and designs, materials and substance, and location and setting. Although some mounds have been damaged by past cultivation or development, many are merely truncated, and the mound bases remain. Contemporary structures, such as the interpretive centre, have been erected on concrete slabs so as not to disturb the underlying archaeological resources. A major highway and railroad traverse the site, but both are minimally visible. The highway is built in the Cahokia Creek floodplain where it does not greatly affect major subsurface archaeological features, and the railroad is built on an embankment.

Known and potential threats to the property include erosion due to both natural and human causes, development, flooding (and flood control actions), and damage to subsurface archaeological features from deep-rooted plant species. 

Protection and management requirements

The property is owned by the State of Illinois and designated by Illinois law as a State Historic Site specifically for its preservation and public interpretation. The core of the State Historic Site has been preserved as a protected public site since 1925. Its archaeological resources are further protected by State law and regulation. The Illinois Historic Preservation Agency, an agency of the State of Illinois, manages the entire property. The updated Master Management Plan (2008) addresses the protection, preservation, interpretation, restoration, and research of the State Historic Site and the State provides professional staff to manage and interpret it for the public. A staffed interpretive centre opened in 1989.

The Master Management Plan and a monitoring program are part of a long-term strategy for the property to aid in addressing known and potential vulnerabilities such as erosion, development, flooding (and flood control), and damage to subsurface archaeological features from deep-rooted plant species.

Links

• Google Arts & Culture: Story
  
• World Heritage in the United States
  
• Illinois Historic Preservation Agency
  
• Cahokia Mounds State Historic Site
  

Media