The furthest North you can go in Minnesota to visit a waterfall without leaving the state or the country is Grand Portage State Park to see the High Falls on the Pigeon River. This waterfall drops 120 feet and was raging at full power when I visited in early May in both 2022 and 2023. It is a short paved and decked walk to the viewing platforms of this mighty waterfall. This is one of the most accessible waterfalls I have visited during my trips to the North Shore of Lake Superior. I will warn you though - you might get wet.