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
Knife River (Lake Superior) Knife River (Lake Superior) The Knife River is a river of northern Minnesota which drains a portion of Lake and Saint Louis counties into Lake Superior between Duluth and Two Harbors. The Knife River's name is an accurate preservation of its native Ojibwe name, "Mokomani Zibi". Its original name was probably given on account of the long, sharp stones near the mouth of the river. The main branch of the Knife River flows from source to mouth, flowing parallel to the shoreline from the direction of Two Harbors. It has four or five major tributaries. Its watershed is , and