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
Eastern Great Lakes and Hudson Lowlands (ecoregion) addition the World Wildlife Fund developed its own classification system, in which much of this region is called the Eastern Great Lakes lowland forests. Eastern Great Lakes and Hudson Lowlands (ecoregion) The Eastern Great Lakes and Hudson Lowlands region extends along the south shores of Lake Erie and Lake Ontario and the St. Lawrence River to Lake Champlain, and south down the Hudson River. It is primarily within the state of New York. In the north it meets the Mixedwood Plains Ecozone of Canada. It is mostly temperate deciduous forest and agricultural land. It is one of the 104 Level