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?
Sentence (from "Patrick Casey House"): 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.
Relevant evidence: Yes