Superior is a town in Pinal County, Arizona, United States. Superior, which is in northern Pinal County, is the oldest town in that county. According to the 2020 census, the population of the town was 2,407. Superior was founded as a mining town for the Silver King and the later Magma mines; silver was mined at first, and then transitioned to copper. Currently, e…Superior is a town in Pinal County, Arizona, United States. Superior, which is in northern Pinal County, is the oldest town in that county. According to the 2020 census, the population of the town was 2,407. Superior was founded as a mining town for the Silver King and the later Magma mines; silver was mined at first, and then transitioned to copper. Currently, exploitation of the huge Resolution Copper deposit is being explored.