Question: What is the name given to a number of elongated iron-ore mining districts around Lake Superior whose cities are known for their architecturally distinctive residences?
Related documents: [0]  [DOC] The Patrick Casey House is a historic house in Aitkin, Minnesota, United States. It was built in 1901 in a mix of Queen Anne and Neoclassical styles. Original owner Patrick Casey (1849–1910) was a partner in the Potter/Casey Company, the region's leading retail chain. The house was listed on the National Register of Historic Places in 1982 for having local significance in the themes of architecture and commerce. It was nominated for its association with one of Aitkin's most prominent businessmen at the turn of the 20th century, and for being one of northern Minnesota's few architecturally distinctive residences outside of Duluth and the Iron Range cities. [END] 
[1]  [DOC] Iron Range refers collectively or individually to a number of elongated iron-ore mining districts around Lake Superior in the United States and Canada. Despite the word "range," the iron ranges are not mountain chains, but outcrops of Precambrian sedimentary formations containing high percentages of iron. These cherty iron ore deposits are Precambrian in age for the Vermilion Range, while middle Precambrian in age for the Mesabi and Cuyuna Ranges, all in Minnesota. Similarly, the Gogebic Range in Wisconsin and the Marquette Iron Range and Menominee Range in Michigan. Natural ores and concentrates were produced from 1848 until the mid 1950s, when taconites and jaspers were concentrated and pelletized started to become the major source of iron production. [END] 
Answer: 
Iron Range
Iron Range