The Wisconsin Historical Society, in partnership with Native Nations in Wisconsin, is excited to share new details from the active archaeological site where two submerged dugout canoes, approximately 1,200 and 3,000 years old, were previously identified. The site drew international attention after divers successfully recovered the dugout canoes in 2021 and 2022, respectively, and today the site remains a source of intrigue for historians and residents as the significance of the discovery expands.
“It is an honor for our team to work alongside the Native Nations to document, research and share these incredible stories from history,” said Dr. Amy Rosebrough, State Archaeologist for the Wisconsin Historical Society. “What we thought at first was an isolated discovery in Lake Mendota has evolved into a significant archaeological site with much to tell us about the people who lived and thrived in this area over thousands of years and also provides new evidence for major environmental shifts over time.”
New Findings
Wisconsin Historical Society Maritime Archaeologist Tamara Thomsen, who is also a member of the Women Diver’s Hall of Fame, explored the depths of Lake Mendota for years before she first happened upon a partially obscured dugout canoe in June 2021, setting the stage for groundbreaking recovery efforts later that November and again in September 2022. While follow-up diving expeditions suggested the presence of additional dugout canoes, Society archaeologists needed time to consult with Tribal partners, analyze findings and document the potentially vulnerable site before publicly releasing details.
Today, researchers have identified at least ten unique canoes—and potentially up to 11 canoes, pending further analysis of wood fragments—in the grouping, including the two previously recovered canoes. Archaeologists hypothesize that the canoes may have been intentionally cached in the water to prevent freezing and warping in the winter months and were later buried by natural forces over time. The Lake Mendota canoes are concentrated along roughly 800 feet of what was likely an ancient shoreline that became submerged over time as a result of environmental shifts in the region. Thomsen recovered a small physical sample from each canoe for carbon dating, wood type analysis, and further research.
“Seeing these canoes with one’s own eyes is a powerful experience, and they serve as a physical representation of what we know from extensive oral traditions that Native scholars have passed down over generations,” said Tribal Historic Preservation Officer for the Ho-Chunk Nation Bill Quackenbush, who focuses on heritage preservation and also specializes in using ground penetrating radar (GPR) technology to research ancestral sites. “We are excited to learn all we can from this site using the technology and tools available to us, and to continue to share the enduring stories and ingenuity of our ancestors.”
Ongoing research leads to new insights
The Wisconsin Historical Society is working in collaboration with Native Nations to research the underwater area adjacent to the canoe cache, as the discovery of the additional canoes reinforces the presence of a submerged habitation site of the Native Nations that have called the area home for millennia. Wood type analysis conducted by the USDA Forest Products Laboratory revealed that the trees used to craft the canoes changed over the years, signaling environmental shifts that impacted forest composition. Elm, Ash, White Oak, Cottonwood, and Red Oak were all used to construct the dugouts, shedding light on which tree species were available as building material at different points in time. The hard woods of the Late Archaic and Woodland periods—Elm, Ash, Cottonwood and White Oak—are challenging for woodworking and their use for dugout canoes also demonstrates the advanced skills and craftmanship of early canoe makers.
Radiocarbon dating results indicated the oldest canoe in the Lake Mendota cache is approximately 4,500 years old—making it the oldest dugout canoe now recorded in the Great Lakes—dating back to around 2500 BC and constructed of Elm. The four oldest of the canoes date back to the Late Archaic period, two of the canoes date to the Middle Woodland period, and up to four canoes date to the Late Woodland period. The most recent canoe is around 800 years old, from the Oneota period, constructed of Red Oak and dating back to around 1250 AD (see timeline graphic).
Quackenbush furthered the research with his ground penetrating radar (GPR) expertise, which is a non-invasive technology frequently used by Native Nations on land to identify ancestral burial sites. Quackenbush was joined by Bad River Band of Lake Superior Chippewa Tribal Historic Preservation Officer Larry Plucinski, and members of the Wisconsin Historical Society archaeology team, to conduct an experimental GPR study on the frozen lake in the winter of 2022 and early 2023. Quackenbush is working to interpret lakebed anomalies that were discovered, and additional GPR studies are planned for the future as ice conditions allow.
Another non-invasive study is being planned in partnership with the Iowa Office of the State Archaeologist and the University of Iowa, utilizing a sonar boat to further research and map the area. Both Plucinski and Quackenbush are collaborators in this effort that is slated to take place later this year.
“We have a lot to learn from the Mendota canoe site, and the research happening today allows us to better understand and share the stories of the people who lived here and had a thriving culture here since time immemorial,” said Plucinski.
The Society will not attempt to recover any additional canoes from the site due to their fragile condition after weathering long-term exposure to natural elements, and later, manmade conditions such as water pollution and boating wakes. The decision was made in collaboration with Tribal Historic Preservation Officers after archaeologists determined that the additional canoes are not physically intact enough to withstand recovery by divers and then the process necessary to preserve the canoes.
Maritime archaeologists from the Wisconsin Historical Society are extensively documenting the site and the canoes still submerged in Lake Mendota, including recording underwater videos and capturing photos of the canoes in situ. Click here to access the gallery with images and video, including documentary-style interviews with archaeologists and historians working on the project.
Looking Forward
While research continues at the Lake Mendota canoe site, the two recovered canoes remain in the Wisconsin Historical Society’s secure storage at the State Archive Preservation Facility in Madison while undergoing a preservation process that uses Polyethylene Glycol (PEG) to stabilize the wood. The treatment takes several years to complete; it began in February 2024 and is expected to conclude in 2026. Once the PEG application is complete, the canoes will be transported to Texas A&M University to undergo a freeze-drying process that leaves the canoes in a stable, solid structure suitable for public display.
The preserved Lake Mendota canoes and the stories of their makers will be shared in the Wisconsin Historical Society’s future Wisconsin History Center when it opens in 2027. The canoes will be part of an immersive, interactive core gallery exploring human connection with land and water throughout history. The preserved historic canoes will help the Wisconsin Historical Society and Native Nations to share these stories in partnership at the future history center.