A groundbreaking study is rewriting the history of agriculture in North America, revealing an unexpectedly vast and sophisticated farming system in a region long considered too harsh for intensive cultivation. Researchers using advanced remote-sensing technology have uncovered a massive network of raised garden beds in Michigan’s Upper Peninsula, created by ancestral Menominee communities between 1000 and 1600 CE. Published in the journal Science, the findings show that these Indigenous farmers extensively modified the landscape to grow maize, or corn, at the northernmost edge of its viability, creating a rich cultural and agricultural hub that challenges previous assumptions about pre-colonial societies.

To peer beneath the dense forest canopy that now covers the site, a Dartmouth-led team, working in partnership with the Menominee Indian Tribe of Wisconsin, employed an innovative surveying technique. They used drone-based LiDAR (Light Detection and Ranging), which pulses laser beams toward the ground to create a highly detailed three-dimensional map of the surface, effectively erasing the trees to reveal the terrain below. “LiDAR is a [potent] tool in any kind of forested or heavily vegetated region where the archaeology is hidden below trees,” said senior author Jesse Casana, a professor of anthropology at Dartmouth. This high-resolution data allowed the team to map an agricultural system far larger and more complex than ever imagined.

The lidar survey and subsequent excavations uncovered an intricate, quilt-like pattern of raised agricultural ridges stretching over 300 acres. These beds, typically 4 to 12 inches high, were not just simple mounds; analysis showed they were carefully constructed and maintained over centuries. The ancestral Menominee enriched the soil with charcoal and household refuse, using it as compost, and transported wetland soils to improve fertility. “Our work shows that the ancestral Menominee communities were modifying the soil to completely rework the topography […] to plant and harvest corn,” said lead author Madeleine McLeester, an assistant professor of anthropology at Dartmouth. The site also contained other significant cultural features, including burial mounds and a ceremonial dance ring, illustrating that the fields were part of a deeply integrated community landscape.

This discovery has profound implications for understanding the history of the Americas. The size of the farming operation, estimated to be 10 times larger than previously thought, suggests a level of labor organization and social complexity not typically associated with the smaller-scale societies believed to have lived in the region. The findings demonstrate that pre-colonial North America contained extensive anthropogenic landscapes—environments profoundly shaped by human activity—that have since been obscured by reforestation. This Michigan site, exceptionally preserved, offers a rare window into a past where Indigenous ingenuity transformed the environment, suggesting that such large-scale agricultural systems may have been far more common across the continent than is currently recognized.

References

• Dartmouth College. (2025, June 13). Archaeologists uncover massive 1,000-year-old Native American fields in Northern Michigan that defy limits of farming. Phys.Org; Dartmouth College. https://phys.org/news/2025-06-archaeologists-uncover-massive-year-native.html
• McLeester, M., Ferwerda, C., Alperstein, J., Overstreet, D., Grignon, D., & Casana, J. (2025). Archaeological evidence of intensive indigenous farming in Michigan’s Upper Peninsula, USA. Science, 388(6751), 1082–1085. https://doi.org/10.1126/science.ads1643