Indian Mounds Mystify Excavators
Oct. 22, 2004
COLLINSVILLE, Illinois -- A thousand years ago along the banks of the Mississippi River, in what is currently southeast Illinois, there was a city that now mystifies both archeologists and anthropologists.
At its zenith, around A.D. 1050, the city that is now called Cahokia was among the largest metropolitan centers in the world. About 15,000 people lived in the city, with another 15,000 to 20,000 residing in its surrounding "suburbs" and outlying farmlands. It was the region's capital city, a place of art, grand religious rituals and science.
But by 1300, the city had become a ghost town, its carefully built structures abandoned and its population dispersed.
Archeologists continue to comb what is now the Cahokia Mounds State Historic Site, looking for clues that will tell them what happened here -- why the city and its culture vanished and why the people who lived here built more than a hundred earthen mounds, many of which are still scattered across the countryside.
Cahokia is not the historical name of this city; the current name comes from the native people who were living in the area when French explorers arrived in the early 1600s. The city's authentic name -- the name given to it by its creators -- is lost to time, as its residents did not appear to have a written language.
But what really puzzles archeologists and anthropologists is that there are no legends, no records, no mention whatsoever of the once-grand city in the lore of any of the tribes -- Osage, Omaha, Ponca and Quapaw -- that are believed to be the direct descendents of the city's builders.
This odd silence on the matter of Cahokia has led some experts to theorize that something particularly nasty happened there. Possibilities include an ugly struggle for power following a leader's death, a government gone berserk, droughts, a period of very cold weather that killed the crops, disease.... All have been put forth as reasons for Cahokia's demise.
Whatever happened, it was bad enough that people just wanted to forget Cahokia, according to Tim Pauketat, an associate professor of archeology at the University of Illinois, who is excavating at Cahokia.
Despite its hard-luck reputation, the Cahokia site feels immensely peaceful today. There's no whiff of angst from an unsettled spirit world, no sense that anything awful happened here.
The 2,200-acre site contains the central portion of what had been roughly a 4,000-acre city. Scattered across the site are about 68 human-made mounds of various sizes, some no more than a gentle rise on the land, others reaching 100 feet toward the sky.
Originally, there might have been more than 120 mounds, but the locations of only 109 have been recorded. Many were altered or destroyed over the last three centuries by farming and construction projects.
The Cahokians made three different types of mounds -- pyramid-shaped (with flat tops upon which important officials' houses and ceremonial lodges were built), ridge-topped and conical. The latter two were used for burials of wealthy citizens and sacrificial victims.
Monks Mound, Cahokia's biggest mound, is a pyramid mound that rises 100 feet from its 14-acre base. Visitors can reach the top by climbing the 141 stairs that pass through the mound's three tiers. Archeologists have found that a large building -- 105 feet long, 48 feet wide and about 50 feet high -- was once positioned on top of the mound. It's believed to have been the home of Cahokia's rulers.
Radiocarbon sampling of the earth that makes up the mound, as well as tools and other artifacts discovered within it, indicates it took 250 years to build Monks Mound, from around A.D. 900 to 1150. The mound was constructed by hauling 22 million cubic feet of dirt from pits located a mile or so away. The dirt was piled into baskets and dragged to the site by workers.
Cahokia also contains five "woodhenges," circles of erect posts that served as celestial calendars, marking the seasonal solstices and equinoxes.
These structures survived for close to two millennia before most were plowed over in the 19th century, paved over in the 20th century or destroyed by archaeologists digging to recover artifacts such as pipes, pottery and other religious relics.
A team from the University of Cincinnati's Center for the Electronic Reconstruction of Historical and Archaeological Sites, has been virtually piecing together the fragments of the immense existing earthworks built by three other prehistoric Native American cultures -- the Adena, Hopewell and Fort Ancient peoples -- in the area that now comprises Ohio, Kentucky, Indiana and Illinois. The people who built Cahokia were of the Mississippian culture.
Using archaeological data gleaned from remote-sensing devices that can detect remains below the ground, and infrared aerial photographs and satellite images to figure out where the earthworks had been located and what they looked like, the University of Cincinnati team is virtually rebuilding the mounds, using standard architectural rendering software. The result will be interactive programs that show how the river valleys of the Midwest would have looked when the mounds were new.
At Cahokia, most of the mounds still exist, though some were destroyed before the site was protected. Two mounds that provided a clear view of a drive-in movie theater's screen several miles away were removed in the 1960s to stop people from watching films for free.
Anthropologists said it's critical to preserve the mounds, which contain many clues about Cahokian culture. While no longer in danger of being leveled for commercial purposes, the mounds are fragile and subject to environmental degradation. State budget cuts have made it difficult to ensure that rain doesn't wash away the remnants of what is the only known prehistoric Indian city north of Mexico.
A recent excavation of a small ridge-top mound -- Mound 72 -- exposed the bodies of nearly 300 people, mostly young women believed to be sacrificial victims, who'd been buried in mass graves. Nearby is the burial site of a man believed to have been a ruler, about 45 years of age, whose body lies on a blanket of more than 20,000 shell beads, surrounded by piles of arrow tips from tribes that inhabited the present-day states of Arkansas, Oklahoma, Tennessee and Wisconsin. They were presumably given as a tribute to the deceased.
Archeologists believe other bodies buried near the ruler are the remains of those who were sacrificed to serve him in the next life. But the skeletons of four men with their heads and hands missing were also found near the largest sacrificial pit, and no one is quite sure why these bodies were mutilated before being buried.
Certainly, a headless, handless body wouldn't make for a good servant.
Every new discovery here raises more questions than it answers about Cahokia, said Bill Iseminger, assistant site manager at Cahokia Mounds.
"I believe that new archeological technology will absolutely allow us to solve many of the mysteries of Cahokia," Iseminger said. "But right now, what with the budget cuts, we're focused mostly on keeping the site intact, just trying to survive so that we can make more people aware of the complexity and brilliance of Native American culture."
Wired news reporter Michelle Delio and photographer Laszlo Pataki have begun their four-week, geek-seeking journey along the Great River Road. If you know of a town they should visit, a person they should meet, a weird roadside attraction they have to see or a great place to fuel up on chili mac, barbecue, gumbo, boiled mudbugs and the like, please send an e-mail to firstname.lastname@example.org.