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
Transportation in Minnesota rivers. Commercial water transportation now is limited to the shipment of bulk commodities on two routes. Barges haul grain and other products down the Mississippi River system from the ports of Minneapolis (the head of navigation), St. Paul, Red Wing and Winona on the Mississippi, and Savage (on the Minnesota River), to downstream river ports, and to ports on the Gulf of Mexico for transshipment to ocean-going cargo ships. Cargo vessels known as lakers haul grain, coal, and iron ore from the Lake Superior ports of Duluth, Superior, Two Harbors, and Silver Bay, through Lake Superior to the lower Great