Excelsior Mining Corp., together with its subsidiaries, engages in the acquisition, exploration, and development of copper mineral properties in the United States and Canada. The company explores for copper oxide and sulfide mineralization with associated molybdenum. It holds a 100% interest in the Gunnison copper project covering an area of approximately 9,560 acres located in Cochise County, Arizona; and the Johnson Camp Mine located in Arizona. The company was incorporated in 2005 and is headquartered in Phoenix, Arizona.