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 of East Dubuque). Highway 61 and parts of Highways 2 and 53 are segments of the Lake Superior Circle Tour route that follows Lake Superior through Minnesota, Ontario, Michigan, and Wisconsin. Duluth International Airport serves the city and surrounding region with daily flights to Minneapolis and Chicago. Nearby municipal airports are Duluth Sky Harbor on Minnesota Point and the Richard I. Bong Airport in Superior. Both the Bong Airport and Bong Bridge are named for famed World War II pilot and highest-scoring American World War II air ace Major Richard Ira "Dick" Bong, a native of nearby Poplar, Wisconsin. Located