WASHINGTON(AP)—A federal appeals court ruled Friday that the Interior Department must account for century-old land royalties owed to American Indians, reversing a lower court’s ruling that the task is impossible.

A 2008 decision by U. S. District Judge James Robertson said Interior had unreasonably delayed an accounting but added that the complicated task was ultimately impossible. He later ruled the Indian plaintiffs are entitled to $455 million, a fraction of the $47 billion or more they have said they are owed.

The appeals court said Friday that that court erred in freeing the government from the accounting burden.

The long-running suit, first filed 13 years ago, claims the Indians were swindled out of royalties overseen by the Interior Department since 1887 for things like oil, gas, grazing and timber.