Wisconsin Historical Society maritime archaeologist Tamara Thomsen in partnership with Ho-Chunk Nation Historic Preservation Officer Bill Quackenbush, Tribal Historic Preservation Officer of the Bad River Band of Lake Superior Chippewa Larry Plucinski and University of Wisconsin-Madison professor Sissel Schroeder have been working together for five years to map the locations of dugout canoes in Lake Mendota, not to recover them from the water, but to study them in place. In addition to locating another 14 canoes, the team has taken samples from each of the ancient vessels with the goal of identifying the type of wood used and their ages.
Analysis conducted by the USDA Forest Products Laboratory has found that half of the 16 canoes were made either of red or white oak. Radiocarbon dating found that the oldest canoe mas made around 5,200 years ago, older than the Great Pyramid of Giza, making it the third oldest in North America. (The oldest two are around 7,000 years old and were found in Florida.)
The prevalence of oak—and particularly red oak, which is not typically used for watercraft due to its tendency to absorb water—prompted Thomsen to examine the reasoning behind its use for canoe building.
“When you look at the shoreline map with canoe locations charted, it’s clear that there are two distinctive groupings represented,” said Thomsen. “Looking at the tree species taxonomy, we wondered not just why certain trees were used by the builders but also why these canoes were situated in these two locations. Carbon dating from the samples told us that both spots were in use over thousands of years, and so we started to form theories as to why they were left where they were and why certain trees were used.” […]
Oak wood, along with some of the other species represented in the samples, is known to form tyloses when the tree encounters stress during the growth cycle such as through wounding or pathogen infection. Tyloses also form as a natural part of a tree’s aging process. During the production of tylosis, balloon-like structures form inside of the wood’s vessels which blocks water movement—preventing the spread of fungi and bacteria and compartmentalizing injuries to protect the wood from decay. As a result, the tyloses make the wood better suited for boat building due to its increased water resistance, buoyancy and protection against rot.
“It’s entirely possible that the canoe builders were intentionally selecting trees that had been damaged from weather or purposefully wounding them during their growth cycle to induce tyloses. We think of bioengineering as a modern practice, but the samples we have suggest this may have been taking place long before the term was coined in the mid-20th century,” said Thomsen.
The canoes could facilitate access to natural resources from the lake like fish—as suggested by the seven net sinkers found with Canoe #1 and three found with Canoe #13—but could also make travel more efficient between communities for trading and to access places of spiritual importance, such as Lake Wingra. The landscape around Madison lakes looked very different before European settlers arrived in the area and conducted terraforming to suit modern transportation, with large bluffs that made traveling over the land difficult in some areas. Canoe travel may have been more efficient for certain routes for the communities who lived in the area spanning thousands of years before Wisconsin became a state.
* This article was originally published here
