Excelsior is a mineral exploration and development company that owns the Gunnison Copper Deposit, the Johnson Camp Mine, and a portfolio of exploration projects, including the Peabody Sill and the Strong and Harris deposits, in Cochise County, Arizona. The past producing Johnson Camp Mine is in Stage 2 of a process with Nuton LLC, a Rio Tinto Venture to restart the mine using Nuton technologies, with first copper expected to be produced in 2025.