Maize may have more importance in pre-European Michigan than previously thought

 

Indigenous people who were the first to inhabit the area now known as Michigan — before the Europeans arrived — may have cultivated maize (corn) more prominently than previously assumed for such a northern population. Researchers from the University of New Hampshire found that using modern global satellite data in a novel way helped them connect archaeological features — like ancient burial mounds — to environmental   data of lake temperatures and gain new insights into past human–environment relationships.

In their study, published in the journal Proceedings of the National Academy of Sciences, or PNAS, the researchers compared ten years of modern temperature data (2014 – 2024), obtained from NASA’s Landsat 8 satellite thermal sensor, to the locations of burial mounds built between A.D. 1200 and A.D. 1600. Through this process the researchers were able to analyze the temperature patterns across thousands of Michigan’s inland lakes. They found that Indigenous communities in the Great Lakes area, known as the Anishinaabeg, built burial mounds near lakes that warmed later in spring, cooled later in fall and were more circular than lakes without mounds. This suggests that placement of the mounds may have been associated with an extended maize-growing season, hinting at a greater cultural role and ceremonial significance for maize than previously thought.

“When we ran this model and we looked at the temperature of lakes and the association of burial mounds with inland lakes, what became really clear is [indigenous people] were understanding their environment so much that they're putting their mounds on lakes where they can grow corn right into an extended fall season,” said Meghan Howey, professor of anthropology and lead author. “There may even be more of a story that they were also growing maize in sophisticated and complicated ways.”

The researchers focused on maize which is a Mesoamerican crop that transformed the early societies that domesticated it for everyday living. Maize has been widely considered a marginal crop to Indigenous people in cold climates like the Great Lakes.

Burial mounds are important ceremonial monuments that signaled a shift in how Anishinaabeg communities in Michigan’s lower peninsula related to places and used resources like maize.

“When you put the ancestors somewhere, you’re staking more of a claim to your resource territories and you’re creating paths for people to come back and visit those places and remember them,” said Howey.

The global satellite-based work — done by co-author Michael Palace, associate professor of Earth sciences and a remote sensing expert — taps into a method of connecting Landsat satellite data with temperature values that Palace previously used to track cyanobacteria and algae blooms in New England lakes. Archaeologists have long used drones, satellites and even hot-air balloons to discover archaeological sites from the sky but utilizing geospatial tools to find relationships between landscapes and ecosystems represents a new frontier.

“It's a cool example of taking a free global data tool developed for an ecological application and using it for archaeological research,” said Howey.

The researchers say that study’s methodology is easily replicable, making it adaptable for analyses across the globe, advancing data-driven and landscape-focused archaeology.