The Trump administration defended the federal government's decision to block the proposed Pebble Mine in southwest Alaska during oral arguments in federal court last week, marking an unexpected stance from an administration that has broadly promoted expanded resource development in the state.

According to Greenwire and E&E News, EPA attorney Laura Brown argued that the agency's decision to prohibit the project remains legally justified, despite recent court rulings that have narrowed the scope of the Clean Water Act and limited federal agencies' regulatory authority.

Brown told the court that the proposed Pebble Mine would have unacceptable impacts on Bristol Bay, home to the world's largest wild sockeye salmon fishery, as well as thousands of acres of fish-bearing streams and wetlands.

"The record fully supports EPA determination that [the project's] proposed discharges into waters of the United States will have an unacceptable adverse effect on spawning fishery areas," Brown argued during the hearing. "Congress authorized EPA to use both its discretion and expertise in making that determination."

Pebble Partnership has argued the EPA's veto should be reconsidered following a 2023 U.S. Supreme Court decision that narrowed federal jurisdiction over wetlands and streams under the Clean Water Act. Brown rejected that argument, maintaining that the agency's decision remains supported by the administrative record.

She also cited another recent Supreme Court ruling that ended the longstanding practice of courts deferring to federal agencies' interpretations of regulations, arguing that while the legal standard has changed, courts should still respect agencies' expert scientific determinations.

The case marks a notable departure from the Trump administration's broader push for increased energy and mineral development in Alaska, as federal attorneys continue defending the EPA's Biden-era decision to block the controversial copper and gold mine.