Long Lake is a small city in Hennepin County, Minnesota, United States named after the lake the eastern end of town lies on. A commercial h…Long Lake is a small city in Hennepin County, Minnesota, United States named after the lake the eastern end of town lies on. A commercial hub for the surrounding communities, Long Lake is home to many local shops and businesses. U.S. Highway 12 runs through the town. The population was 1,768 at the 2010 census.