Mount Isa (/ ˈ aɪ z ə / EYE-zə) is a city in the Gulf Country region of Queensland, Australia.It came into existence because of the vast mineral deposits found in the area. Mount Isa Mines (MIM) is one of the most productive single mines in world history, based on combined production of lead, silver, copper and zinc.. With an estimated urban population of 21,998 as at June 2016, Mount Isa ...