PolyMet Mining Corp., through its subsidiary, Poly Met Mining, Inc., engages in the exploration and development of natural resource properties. Its primary mineral property is the NorthMet project, a polymetallic project that hosts copper, nickel, cobalt, gold, silver, and platinum group metal mineralization covering an area of approximately 4,300 acres located in northeastern Minnesota, the United States. The company was formerly known as Fleck Resources Ltd. and changed its name to PolyMet Mining Corp. in June 1998.