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
Duluth, Minnesota and is water. It is Minnesota's second-largest city by land area, surpassed only by Hibbing. Of its , , or 77.89%, is land and , or 22.11%, is water. Duluth's canal connects Lake Superior to the Duluth–Superior harbor and the Saint Louis River. It is spanned by the Aerial Lift Bridge, which connects Canal Park with Minnesota Point ("Park Point"). Minnesota Point is about 7 miles long, and when included with adjacent Wisconsin Point, which extends 3 miles from the city of Superior, Wisconsin, is the largest freshwater baymouth bar in the world at a total of 10 miles. Duluth's