A federal appeals court panel Friday halted an exploratory gold drilling project in the eastern Sierra Nevada that was set to begin this week. Kore Mining Ltd. planned to drill for gold near Mammoth Lakes. The project involved 12, 600-foot deep holes on some 1,900 acres. It would have required vegetation clearing and less than a mile of temporary access roads. Four groups — Friends of the Inyo, the Center for Biological Diversity, the Western Watersheds Project and the Sierra Club — sued Kore Mining and the U.S. Forest Service in October 2021, arguing the drilling would impact area groundwater that feeds into the Owens River and cause the bi-state sage grouse to abandon its habitat. A federal judge in March sided with the defendants.