Black Eagle is a census-designated place in Cascade County, Montana, United States. The population was 904 at the 2010 census. It is part of the Great Falls, Montana Metropolitan Statistical Area.With early activity from smelters and refineries, Black Eagle was first called "Little Chicago". This was a reference to the industrialized nature of the town. When the post office was established in 1917 the name of the town officially became Black Eagle. It was named for the Black Eagle Falls on the Missouri River, which were named by Capt. Meriwether Lewis.Construction of the Boston & Montana smelter, which formed the town's skyline, began in 1891. It was demolished on September 18, 1982.