The Cahokians were late Woodland Indians that first settled in the Cahokia area in approximately 700 A.D. They were considered Mississippian Indians because they settled approximately 12 miles from the Mississippi River, near present-day St. Louis in Collinsville, Ill. They hunted, fished and farmed, surrounding the outside of the city with crops such as squash, sunflowers and corn. This growing community developed structured social classes and political and social systems.

Cahokian civilization peaked from 1050 to 1200 A.D. and became a central area for surrounding towns. It was the largest city north of Mexico, spanning over six square miles and housing anywhere from 10,000 to 20,000 people.

Lila Vick, volunteer and tour guide, has worked at Cahokia Mounds for 16 years.

“It’s the idea of telling people about who was here before them and about the way they lived and what they believed in,” Vick said. “What happened here helps us understand any society ... There’s lessons to be learned from knowing about past civilizations.”

Cahokia Mounds was a community that once covered approximately 4,000 acres and boasted more than 120 earthen mounds. Seventy of these are still present and protected on the now 2,200-acre site. The reason for Cahokia’s decline, around 1300 A.D., is still unknown, but experts think it might be a result of climate changes, lack of resources, overpopulation or societal conflicts.

Site Highlights

The Cahokians built several types of mounds, each with a specific purpose. Researchers think that more than 50 million cubic feet of earth was transported to create these structures.  Ridgetop and conical mounds were used for burials of important people or to mark important locations. Rectangular-based mounds had buildings atop them. The largest mound is Monks Mound, which was possibly intended as housing for the paramount chief or for ceremonial purposes.

Vick said a visitor favorite is climbing to the top of Monks Mound.  She said the awesomeness of the more than 14-acre base, 100-foot high mound can’t be fully comprehended until visitors stand at the top and imagine what it must have been like to build it.

Gazing out from the top of Monks Mound, visitors can see the St. Louis skyline and a view of other mounds scattered throughout the site. Monks Mound is the largest man-made earthen mound in North America and originally had stairs and four terraces to the top. Excavations have revealed that a building was once at the top of the mound, indicating it was possibly the home of the Cahokian leader or used for ceremonial purposes.

Kathy Miles said the most interesting fact she learned during her visit was that Monks Mound might have been where the paramount chief lived, because she would have expected the largest mound to be for something else, like burials. She said it was unbelievable that the Cahokians built the mounds themselves by carrying dirt on their backs. “It’s amazing what [they] did with no modern tools — no bulldozers,” Miles said.

Excavations of one ridgetop mound have shown that approximately 300 burials took place there, almost completely of women. The sole exception, an elite male, estimated to be approximately 45 years old, was buried there upon 20,000 beads made out of seashells that were in the shape of a bird, Vick said. Besides the mounds, there are other nearby Cahokia attractions.

Woodhenge, built from 1100 to 1200 A.D., is a large circle of posts built from 1100 to 1200 A.D. that is seven-feet tall, more than two-feet wide and was used as a sun calendar by the Cahokians. Posts were aligned with the winter and summer solstice and the spring and fall equinox. Other posts might have served as markings for festival dates and observation posts.

In the 1960s, Dr. Warren Wittry found oval-shaped pits arranged in circles, revealing that Woodhenge was built possibly as many as five times. In 1985, the third circle, 410 feet in diameter, was reconstructed so visitors could view it and get a sense of what Woodhenge might have originally looked like.

Discovering Cahokia

Assistant Site Manager Bill Iseminger said the site has changed dramatically throughout the years. In 1921, researcher Warren Moorehead came to Cahokia Mounds and excavated core samples from Monks Mound to establish that the mounds were man-made, putting an end to the debate of whether the mounds were natural to the landscape.

Since then, more than 100 excavations or research projects have taken place at Cahokia. The site is continually expanding to include more mounds — since 1925, the site has grown from 244 acres to 2,200. There has been some type of archaeological project on the site each summer since the late 1960s. Iseminger said they are still working to acquire more land for the site to protect additional mounds on other property.

Area universities have had groups of students and faculty at the site to excavate. One group reopened an old dig that contained evidence of a copper workshop that might have been used to produce various religious items.

Cahokia Mounds was designated as a World Heritage Site in 1982. Cahokia Mounds is one of 21 World Heritage Sites in the United States, including the Statue of Liberty and Yellowstone National Park.

Cahokia Today

Mounds aren’t currently being excavated because excavations virtually destroy the mounds, Vick said.

However, visitors can take tours of the other excavation sites in the areas around the mounds on Archaeology Day to see artifacts that have been found at the site and watch artifact processing. Volunteers from Cahokia Mounds, like Vick, can participate in excavations. The archeologists have found a bit of everything, from pottery pieces and stone tools to animal bones and fish scales, she said.

Other researchers are using a variety of remote-sensing instruments to try to determine features below the surface and help direct future excavations.

“It’s not like Indiana Jones,” Vick said. “It’s hard, it’s dirty, but when your trowel hits something that hasn’t seen the light of day in a thousand years ... you have a connection.”