Scientists Using LIDAR to ‘See’ Through the Dense Forest Canopy Make a Surprising 1,000-Year-Old Discovery
Dartmouth Scientists using drone-mounted LIDAR to study the forests of Michigan’s Upper Peninsula report the discovery of a sophisticated, 1,000-year-old farming community that defies previous assumptions about the precolonial Americas.
Follow-up excavations confirmed the site’s age and scale, potentially forcing scientists to reassess the organization and sophistication of ancient farming communities worldwide.
“The scale of this agricultural system by ancestral Menominee communities is 10 times larger than what was previously estimated,” says Madeleine McLeester, an assistant professor of anthropology at Dartmouth and the lead author of the study detailing the team’s discoveries. “That forces us to reconsider a number of preconceived ideas we have about agriculture, not only in the region, but globally.”
Modern LIDAR Technology Makes 1,000-Year-Old Discovery Possible
The Dartmouth team’s study focused on a site in Michigan’s Upper Peninsula called Anaem Omot, which stands for the “Dog’s Belly” in Menominee. Because LIDAR was not available in numerous previous studies of the site dating back to the 1950s, the Menominee tribal authorities asked the researchers to survey and document the area using the new technology.
The initial expedition began in May 2023 after the winter snow had finished melting but before Spring leaves filled the trees. Unlike archaeological excavations that look for artifacts at or below ground level, the team’s initial effort used drones equipped with LIDAR to scan the area from the sky. Because the method uses pulses of laser light to gather topographical information, it can “see” through the dense forest canopy even if there is no line of sight to the target.
“Lidar is a really powerful tool in any kind of forested or heavily vegetated region where the archaeology is hidden below trees—where no kind of optical imagery can see what’s underneath the tree canopy,” explained Jesse Casana, a professor of anthropology who uses remote sensing technologies regularly in his work and the study’s senior author.
The professor said dense forests are particularly “confounding” to archaeologists, causing them to rely on publicly available LIDAR surveys. Still, most of those LIDAR scans were captured by high-flying aircraft, often limiting what archaeologists can learn from them. The team believed that drones capable of flying much lower than aircraft could dramatically increase the scans’ resolution and overall data quality.
“The resolution of the data is usually too low to see many archaeological features, “Casana explained. “Drone lidar enables us to collect the same kind of data but at a much higher resolution.”
Drone Scans Reveal Previously Invisible Ancient Activity
According to the team’s study, their LIDAR-equipped drones surveyed a 330-acre area. They estimate this segment represents roughly 40% of the larger site, with the remaining portion still unmapped.
Analysis of the scans revealed several interesting features, including sets of parallel “ridges” that formed “quilt-like” patterns spread across the ancient landscape. Because the ridges were constructed in varying directions that didn’t appear to align with the direction of the sun or other aspects of the local environment, the team suspects the ancient farming tracts may have been determined by individual farmers.
Among the most shocking discoveries was the overall scale of the 1,000-year-old farmland. According to the research team, nothing in the previous literature about the pre-colonial native populations suggested they were farming at this scale and with this level of communal organization.
“When you look at the scale of farming, this would require the kind of labor organization that is typically associated with a much larger, state-level hierarchical society,” says McLeester. “Yet, everything we know about this area suggests smaller egalitarian societies lived in this region, but in fact, this may have been a rather large settlement.”
Other LIDAR discoveries included a circular “dance” ring, a building foundation the researchers suspect may have served as a colonial trading post, and two logging camps dated to the 1800s. Several looted burial mounds were spotted, including some unknown mounds thought destroyed five decades earlier.
Excavations Confirm Shocking Findings
Three months after the LIDAR scans revealed the outlines of a 1,000-year-old farming community, the Dartmouth team performed excavations of three of the raised agricultural ridges. Radiocarbon dating performed on samples taken from sites at varying distances from the Menominee River revealed a 1,000-year-old initial settlement under several later layers of human activity covering a 600-year period. Casana says all three ridges “showed a similar picture” regarding construction, history, and reconstruction.
Additional excavations turned up broken ceramic pieces called ‘sherds,’ charcoal, and other artifacts that suggested these ancient people used the remains from fires and other household refuse as compost. Further inspection of the ancient farmland ridges showed the use of wetland soil to enrich the farmland soils, adding to the picture of unexpectedly sophisticated ancient farming.
“Our work shows that the ancestral Menominee communities were modifying the soil to completely rework the topography in order to plant and harvest corn at the near northern extent of where this crop can grow,” says McLeester. “This farming system was a massive undertaking requiring a lot of organization, labor, and know-how to maximize agricultural productivity.”
Christopher Plain is a Science Fiction and Fantasy novelist and Head Science Writer at The Debrief. Follow and connect with him on X, learn about his books at plainfiction.com, or email him directly at christopher@thedebrief.org.
