For the past few years, Thomsen has been collaborating with the preservation officers with the Ho-Chunk Nation and the Bad River Band of Lake Superior Chippewa, as well as Sissel Schroeder, an anthropologist at the University of Wisconsin, Madison, and the U.S. Department of Agriculture’s Forest Products Laboratory. Together, they’re unraveling the mysteries of the Indigenous canoes, which are some of the oldest surviving specimens of their kind in eastern North America.