Amid continuing protests over an oil pipeline set to run close to the Standing Rock Sioux Reservation in North Dakota, the US Department of the Interior has announced it is cancelling 15 oil and gas leases in neighbouring Montana, on land considered sacred to the Blackfoot tribes of the US and Canada.

The move will preserve a 130,000-acre wilderness known as the Badger-Two Medicine area, which is the site of the tribes’ creation story and a key habitat for grizzly bears, elk and other species. It adjoins the Blackfeet Nation and Glacier National Park. US interior Secretary Sally Jewell said on her department’s website that the cancellation would protect the area’s “rich cultural and natural resources” from the “irreparable impacts [of] oil and gas development.”

Speaking in Washington DC on Wednesday, Ms Jewell said the decision “sets the right tone for how business should be done in the future.” According to the Associated Press, the leases were issued to Devon Energy, an Oklahoma-based company, in the early 1980s without proper consultation with tribal leaders.

No drilling has been done on the sites over the ensuing decades, and Devon’s President David Hager described the cancellation as “the right thing to do”. The firm agreed to give up the leases for a refund of just over $200,000. Another energy lease in the same region was also cancelled earlier this year.

The agreement stands in stark contrast to the Obama administration’s handling of the Standing Rock situation. Federal officials have said they will consider re-routing the pipeline away from Sioux land. But on Wednesday a United Nations human rights expert accused US security forces of using excessive force to subdue the protests over the pipeline.

Maina Kiai, the UN Special Rapporteur on the rights to freedom of peaceful assembly and association, said in a statement that some of the 400 people detained during the unrest had been subjected to “inhuman and degrading conditions.”