The Northland Pyrite Mine, also known as James Lake Mine, Rib Lake Mine, Harris Mine or simply Northland Mine, is an abandoned underground mine in Northeastern Ontario, Canada, located on the southwestern shore of James Lake in Best Township of Temagami. It was operated by the Northland Mining Company during the early 1900s with the construction of a 91 m (299 ft) shaft and many open-cuts north of the shaft. Minerals present at the mine include chalcopyrite, pyrite and pyrrhotite, deposited in Precambrian volcanic rock of the Canadian Shield.