Cahokia flooding and decline begins

1150

The Mississippian city across from modern St. Louis suffered a series of floods of the Mississippi River that damaged its ceremonial plazas. Combined with worsening drought on the western prairies, the stresses began a long demographic decline that would empty the city within two centuries. Archaeological evidence suggests that deforestation of the surrounding uplands for fuel and construction worsened the flooding, creating a spiral of environmental degradation.