Excelsior Mining Corp. announced that the amended permit to the Class III Underground Injection Control ("UIC") Area Permit, that allows for well stimulation to occur at the Gunnison Copper Project, located in Cochise County, southeastern Arizona is now effective as of May 26th 2023. The amended permit was originally issued on April 21, 2023 but was not effective until the expiry of the appeal period.

The appeal period has ended without an appeal being filed and as a result the amended permit is now in effect. Well stimulation has the potential to fundamentally change the performance of the wellfield, and eliminate or reduce the need for the raffinate neutralization plant. Excelsior intends to proceed to field trials in early H2 of 2023.

Excelsior will submit the well stimulation work plans required by the permit and schedule the necessary contractors in the near term.