WASHINGTON— The Center for Biological Diversity and Sovereign Iñupiat for a Living Arctic sued the federal government today for reviving Hilcorp Alaska LLC’s expired oil and gas drilling leases for the proposed Liberty Unit project. Liberty would be the first oil drilling project fully within federal waters in the Arctic Ocean.

The Biden administration denied Hilcorp’s lease extension request in December 2024 and the leases were terminated. In November 2025 the Trump administration purported to reverse the denial under the pretense of a national energy emergency.

“The Beaufort Sea feeds Iñupiat families, and the bowhead whale is at the center of our way of life,” said Nauriaq Simmonds, executive director of Sovereign Iñupiat for a Living Arctic. “These leases expired because Hilcorp could not meet the basic requirements, including a workable plan for an oil spill in waters covered by sea ice much of the year, the consequences of which could be devastating to our people. Bringing them back under the name of an emergency is Donald's administration setting the law aside for industry. We are asking the court to hold the government to the rules that are meant to protect all of us.”

Today’s lawsuit says drilling activities will disturb numerous vulnerable Arctic animals, including bowhead whales, walrus, ice seals and polar bears. An oil spill in the Arctic Ocean would be all but impossible to contain and clean up, especially because sea ice is present much of the year.

The suit was filed in U.S. District Court for the District of Columbia against the Interior Department and the Bureau of Safety and Environmental Enforcement for violations of the Outer Continental Shelf Lands Act.

“We’re not going to let the Trump administration abuse its power and put the Arctic Ocean in jeopardy by unlawfully raising these leases from the dead,” said Rebecca Noblin, Alaska legal director at the Center for Biological Diversity. “Oil drilling in the Arctic Ocean is as dangerous as it gets and we should increase protections there, not ramp up extraction. The whales, walrus and polar bears in the Beaufort Sea will be at risk of an oil spill if Liberty goes forward, and we’ll keep working to protect them.”

The oldest Liberty Unit lease was sold to BP in 1991 and the Liberty leases were previously extended 11 times. Hilcorp acquired primary ownership and operatorship of the Liberty project from BP in 2014.

In 2018 the first Trump administration approved Hilcorp’s plan to drill at the Liberty Unit. The Center and other environmental groups sued over the approval because it failed to adequately consider the project’s climate impacts and harm to polar bears. The groups won their lawsuit in 2020, with the court vacating the project’s approval.

In December 2024 the Interior Department denied Hilcorp’s request for a one-year lease extension because the company failed to meet regulatory requirements, including failing to provide a revised and completed drilling plan nearly four years after the court deemed the previous plan unlawful. The company also failed to provide an adequate oil spill response plan. Because the Liberty leases are all past their initial 10-year terms, without an extension the leases automatically expired.

Hilcorp appealed the denial in February 2025, but in April 2025 the Trump administration rescinded the denial and the appeal was dismissed. In November 2025 the Trump administration granted Hilcorp a five-year lease extension, through 2029.

To reach the Liberty leases, Hilcorp currently plans to drill horizontally from an existing artificial gravel island that is part of the Endicott project in state waters.