Indian mounds near St. Louis Missouri include the Cahokia Mounds in Cahokia Illinois. St. Louis used to be referred to as ‘Mound City’ because of the earthen mounds that dotted the city. But, except for Sugarloaf Mound, they are all gone. Sugarloaf Mound was bought in 2009 by the Osage Nation and will be preserved.
Cahokia is on the other side of the Mississippi River, and preserved in Illinois’ Cahokia Mounds State Historic Site. The largest mound at the Cahokia site is Monks Mound, around 100 feet tall at its peak and between 235 and 290 meters across. The Cahokia civilization probably peaked around 1200 AD, 900 years ago, just prior to the last global cooling cycle. The size of the settlements in the Cahokia area would not be surpassed by an American city for 500 years, with a population the reached more than 40,000 people. New York City reached that size in 1800.
Excavations in the Cahokia complex of more than 100 mounds include evidence of human sacrifice including layers of 20 year old women and men buried alive. Also evidence has been found of copper smelting and forging. Artifacts thought to be related to the Cahokia culture have been discovered as far north as St. Paul, Minnesota, also on the Mississippi River.