The EPA invoked its rarely-used authority under the Clean Water Act to block the proposed Pebble Mine near the headwaters of Alaska’s remote Bristol Bay watershed on Tuesday. The agency’s final determination under Section 404(c) of the Clean Water Act represents just the 14th time in that law’s 50-year history the EPA has exercised its power to prohibit activity because of the potential impact on water quality and fisheries.

The proposed copper and gold mine would have threatened what EPA administrator Michael Regan described as, “the true irreplaceable and invaluable natural wonder that is Bristol Bay,” along with roughly half the global supply of sockeye salmon, which in turn supports 15,000 jobs, and provides subsistence for Native tribes in the region. The decision, the administration’s third in two weeks protecting pristine ecosystems from resource extraction, was hailed by environmental groups and Alaska Native communities.

The EPA announcement “was a real moment of justice for us,” Alannah Hurley, head of United Tribes of Bristol Bay, told the New York Times. Tribes have been told the mine was inevitable and, “We just need to fall in line,” she added. “Thank goodness our tribal leaders did not accept that … We’ll be celebrating this decision for decades to come.” (New York Times $, E&E News, AP, Washington Post $, Anchorage Daily News, Alaska Public Media, KDLG, 770 KTTH, Inside Climate News, The Hill, Bloomberg $, E&E News, Axios, Roll Call, NBC, Courthouse News, Bloomberg Law, Reuters; Commentary: High Country News, Alannah Hurley interview, Esquire, Charles Pierce commentary)