From their website (be sure to check for updates, as we are posting this link 10 months before it happens)
"The Hawk Ridge Nature Reserve in Duluth, Minnesota is one of North America's best places to experience the spectacle of the fall raptor migration. Migrating birds, including raptors and passerines, concentrate in impressive numbers at the western tip of Lake Superior. Some travel from as far away as the Arctic and pass through Duluth on their way to their wintering areas to the south. Reluctant to cross a large body of water, migrants funnel down the North Shore along the ridges that overlook the city. On a good day, visitors may see hundreds—even thousands—of birds flying by!"
hawks galore! check website about what to bring.