Specially equipped drones flying over a Kansas cattle ranch have detected the buried remnants of a horseshoe-shaped ditch made more than 400 years ago by ancestors of today’s Wichita and Affiliated Tribes, scientists say.
The find adds to suspicions that the Kansas site was part of a sprawling population center that Spanish explorers dubbed the Great Settlement in 1601, archaeologist Jesse Casana of Dartmouth College and his colleagues report August 24 in American Antiquity.
Called Etzanoa by a captive the Spanish took from the Great Settlement, it could turn out to be one of the largest Native American settlements ever established north of Mexico, if confirmed by further research. The largest currently known is Cahokia, a site in what’s now Illinois where as many as 20,000 people lived between 1050 and 1150.
Ancestral Wichita communities in Kansas and northern Oklahoma that date to between around 1425 and 1650 existed in a time frame during which South America’s Inca civilization rose and fell (SN: 8/3/20). In the 1800s, European settlers drove ancestral Wichita people from their native lands, leading to the destruction of their villages and communal traditions.
The newly discovered earthwork, a 2-meter-wide ditch that forms a semicircle about 50 meters across, is similar to other circular earthworks known as council circles. Five council circles have been found among 22 ancestral Wichita sites excavated along an eight-kilometer stretch of the Walnut River.
“We apparently have located the sixth council circle and the only one that has not been disturbed,” says anthropological archaeologist Donald Blakeslee of Wichita State University. Farming and construction projects have damaged or covered many ancestral Wichita sites.
Drone surveys “can truly transform our ability to locate sites and map important features where huge areas have been plowed and surface traces of houses and ditches are often close to invisible,” says archaeologist Douglas Bamforth of the University of Colorado Boulder, who did not participate in the new study.
It’s unclear how ancestral Wichita people used council circles. Researchers have suggested that these structures were places for ritual ceremonies, houses of social elites or protection from attackers.
Based on previous discoveries of items made of obsidian, seashells and other exotic materials at council circles, these structures must have hosted rituals of some kind, says archaeologist Susan Vehik of the University of Oklahoma in Norman. Drone imagery alone can’t establish whether rituals occurred at the buried earthwork or if, perhaps, non-combatants hid behind walls along its borders when the site was attacked. For now, she says, the drone discovery is an intriguing mystery.
Blakeslee was inspired by publications of an archaeologist who excavated at the same bluff site more than 60 years ago and suspected it had been a central part of Etzanoa. Since then, Blakeslee’s excavations along the Walnut River have filled in gaps between ancestral Wichita sites. Etzanoa likely existed as a single, spread-out community, Blakeslee contends. Upstream from Etzanoa sites, excavations have uncovered remnants of a separate Wichita town that ran for about three kilometers, he says.
From 2015 to 2019, Blakeslee directed an excavation at the House family cattle ranch in southeastern Kansas that uncovered ancestral Wichita objects such as stone tools and cooking utensils as well as 17th century Spanish items, including a horseshoe nail and bullets. These finds supported Spanish documents and maps of Etzanoa that resulted from the 1601 expedition to Wichita territory, and led the Kansas state legislature in 2017 to designate the site and its surrounding area as Etzanoa.
Blakeslee’s artifact discoveries also led to the new drone survey. Casana directed aerial sweeps over grazing land at the cattle ranch, where ancient structures had likely suffered minimal damage. Drone-mounted equipment measured heat and radiation differences in the ground to detect buried structures.
The underground earthwork at the House ranch lay near the highest point of the property, overlooking the river valley. Other circular earthworks of the ancestral Wichita and neighboring groups in the southern Great Plains were also built at elevated spots, Casana’s team says.
Drone imagery also picked up signs of two pits, one dug at or near each end of the semicircular structure. Makers of the earthwork may have removed soil from the pits to construct mounds inside its borders, as has been observed at excavated council circles in the region. Erosion may have partly worn away what was originally a circular earthwork, the researchers speculate.
Blakeslee plans to explore more underground features of the Kansas site with additional remote sensing techniques before starting excavations so that digging can precisely target the earthwork and any surrounding remains. That will also up the likelihood of uncovering material suitable for radiocarbon dating and revealing the age of the earthworks.