Great Lakes tectonic zone southern Ontario. Several earthquakes have been documented in Minnesota in the last 120 years, with at least six in the GLTZ. The epicenters show a clear relationship to tectonic features of the state; four epicenters lie along the Great Lakes tectonic zone. Depths are estimated at . The best-documented event occurred on July 9, 1975, near Morris, Minnesota, with a magnitude of 4.6, and a felt area of covering parts of four states. Wisconsin has had no earthquakes along the GLTZ, Michigan's Upper Peninsula has had four earthquakes in the vicinity of the GLTZ – Negaunee, Newberry and two in
Great Lakes region Hudson, Mohawk and Susquehanna form an arc of watersheds east to The Atlantic. The Great Lakes region, as distinct from the Great Lakes Basin, defines a unit of sub-national political entities defined by the U.S. states and the Canadian Province of Ontario encompassing the Great Lakes watershed, and the states and Province bordering one or more of the Great Lakes. Prior to European settlement, Iroquoian people lived around Lakes Erie and Ontario, Algonquian peoples around most of the rest, and a variety of other indigenous nation-peoples including the Lakotan, Ojibwa, Illinois, Pottawatmie, Huron, Shawnee, Erie, Fox, Miami, Crow and Ho-Chunk