A groundbreaking discovery in Michigan’s Upper Peninsula is changing what we thought we knew about ancient farming in North America.
Archaeologists have uncovered an enormous and well-preserved system of raised agricultural fields created by the ancestors of the Menominee Indian Tribe of Wisconsin.
These fields, which are around 1,000 years old, were found near the Menominee River at a site called Sixty Islands.
Despite the area’s cold climate, short growing season, and dense forests—conditions considered harsh for farming—this discovery proves that large-scale, organized agriculture was happening here long before European contact.
The study, led by Dartmouth College and published in Science, reveals that this is the most complete ancient farming system ever found in the eastern U.S.
The fields are made up of small raised garden beds, each about 4 to 12 inches high. These beds were used to grow crops such as corn, beans, and squash.
What’s most surprising is the massive size of the field system—it’s about ten times larger than experts previously believed. Researchers surveyed about 330 acres, but they estimate this is only 40% of the entire site.
Lead researcher Madeleine McLeester explained that the scale of the farming suggests a high level of planning and organization, which is normally associated with large, complex societies.
Yet this area was home to smaller, more equal (egalitarian) communities, which now seem to have been far more advanced in farming than previously assumed.
The Sixty Islands site is part of a larger area known as Anaem Omot, meaning “Dog’s Belly” in the Menominee language.
This region holds deep cultural importance and includes burial mounds, dance rings, and the remains of ancient villages. It’s also listed on the U.S. National Register of Historic Places.
To better understand the site, Dartmouth archaeologists worked closely with the Menominee Tribe. In May 2023, they used drones equipped with lidar technology—a kind of laser mapping that can see through trees and vegetation.
The high-resolution scans revealed detailed ridges and patterns across the landscape, as well as structures like a circular dance ring, the possible remains of a trading post, and even logging camps from the 1800s. They also discovered burial mounds thought to have been lost.
In August 2023, the team excavated three of the ancient ridges. They found charcoal and broken pottery, suggesting that fires and household waste were likely used as compost.
Radiocarbon dating showed that the fields were used and rebuilt over a period of 600 years, starting around the year 1000. Researchers also discovered that farmers enriched the soil by adding nutrients from wetlands.
These findings challenge the idea that the Upper Peninsula was always heavily forested, as the area must have been cleared for centuries to support this level of farming. It also makes researchers wonder if similar agricultural ridge systems once covered much of eastern North America, only to be erased by modern development and farming.
According to McLeester, this farming system was “a massive undertaking,” showing how deeply knowledgeable and organized these Native communities were. The research gives a rare glimpse into pre-colonial life and highlights the lasting legacy of Indigenous land stewardship.
The team plans to continue working with the Menominee Tribe to uncover more about the ancient villages in the area and to expand their survey of this remarkable site.
