Grand Portage is an unorganized territory in Cook County, Minnesota, United States, on Lake Superior, at the northeastern corner of the state near the border with northwestern Ontario. The population was 616 at the 2020 census. The unincorporated community of Grand Portage and the Grand Portage Indian Reservation are both located within Grand Port…Grand Portage is an unorganized territory in Cook County, Minnesota, United States, on Lake Superior, at the northeastern corner of the state near the border with northwestern Ontario. The population was 616 at the 2020 census. The unincorporated community of Grand Portage and the Grand Portage Indian Reservation are both located within Grand Portage Unorganized Territory of Cook County.