HELENA, Mont. — A federal appeals court ruled Tuesday to cancel a long-disputed oil and gas lease on land in northwestern Montana considered sacred to tribes in the U.S. and Canada.

The three-judge panel of the U.S. Court of Appeals for the District of Columbia Circuit overruled a judge’s 2018 decision that had allowed a Louisiana company to keep its lease within the Badger Two-Medicine area of Lewis and Clark National Forest.

That area near Glacier National Park is the site of the creation story of the Blackfoot tribes of southern Canada and Montana’s Blackfeet Nation.

John Murray, the Blackfeet’s tribal historic preservation officer, said the court’s decision will close a “long and painful chapter in the history of our people.”

“These leases should never have been issued in the first place,” Murray said. “Today’s ruling shows that these companies and their lawyers were not just on the wrong side of history but were also on the wrong side of the law when they waged their 40-year crusade to drill our ancestral land.”

“Our traditional practices and traditional lands are the firm ground underfoot that we need to push off into the future,” said Tyson Running Wolf. Running Wolf is a Montana state legislator, former Blackfeet Tribal Business Council member, hunting outfitter and leader among Blackfeet traditionalists. “This is how we heal ourselves, how we heal our communities, how we move forward into success. The Badger-Two Medicine is more than just land; it’s an entire way of life.”

Tim Preso, Earthjustice attorney, argued the case on behalf of intervenors including Blackfeet Headwaters Alliance, Pikuni Traditionalist Association, Glacier-Two Medicine Alliance, Montana Wilderness Association, National Parks Conservation Association and The Wilderness Society. These organizations have since joined the Blackfeet Nation in calling for permanent protection of the Badger-Two Medicine.

The lease owned by Solenex LLC was the last active exploratory lease of about 45 issued in the Badger-Two Medicine area since the 1980s.

“We’re obviously very disappointed in the panel’s decision today, particularly their refusal to engage with any of the arguments we raised on appeal,” said David McDonald, attorney for Solenex, which is owned by Sidney Longwell. “We fully intend on continuing to fight for Solenex and the Longwell family, and we’re currently considering all available avenues to do so.”

The company has held the lease for more than 30 years. It had not yet drilled because of bureaucratic delays within the U.S. departments of Interior and Agriculture, prompting the company to sue in 2013.

The U.S. government canceled the lease in 2016, saying a proper environmental analysis had not been conducted, a decision Solenex challenged. A federal judge sided with the company in 2018, saying the long amount of time between the lease being issued and canceled violated federal law.

The three-judge appellate panel ruled the judge’s findings were wrong and that the the government had considered Solenex’s interests.

“Delay by itself is not enough to render the lease cancellation arbitrary or capricious,” the ruling said.