Duluth, Minnesota four Catholic schools with coverage up to grades 6 or 8, two Protestant schools, two Montessori schools, and six other charter and private schools. Due to its proximity to the Great Lakes, Duluth is the location for the Large Lakes Observatory. The Large Lakes Observatory operates the largest university-owned research vessel in the Great Lakes, the R/V Blue Heron. Built in 1985 for fishing on the Grand Banks, the Blue Heron was purchased by the University of Minnesota in 1997, sailed from Portland, Maine, up the St. Lawrence Seaway to Duluth, and converted into a limnological research vessel during the
Geology of Minnesota the Minnesota and Mississippi Rivers. Eventually, the ice sheet melted, and the Red River gave Lake Agassiz a northern outlet toward Hudson Bay. As the lake drained away its bed became peatlands and a fertile plain. Similarly, Glacial Lake Duluth, in the basin of Lake Superior, was dammed by a glacier; it drained down the ancient course of the Midcontinental Rift to the St. Croix River and the Mississippi. When the glaciers receded, the lake was able to drain through the Great Lakes to the Saint Lawrence River. Giant animals roamed the area. Beavers were the size of bears, and