President Obama has pointed a way out of a dangerous standoff over an oil pipeline being built in North Dakota. He told an interviewer on Tuesday that the Army Corps of Engineers was looking for a new pipeline route, presumably away from the Standing Rock Sioux Reservation, whose members and allies have been protesting the project for months, saying it threatens the tribe’s sacred lands and water supply.

It was a welcome hint of good news in an intensely bitter confrontation that came wrapped in historic injustice and seemed destined to end in grief. The $3.7 billion Dakota Access pipeline is meant to carry crude oil from the Bakken fields of western North Dakota to Illinois, 1,170 miles to the east. It would not enter tribal land but it would pass close enough for the Sioux to fear grave damage from a leak or spill. Its current proposed route runs less than half a mile north of the reservation and under the Missouri River, a source of drinking water. Though the pipeline would mostly cross private property, the tribe also argues that these have been the Sioux’s ancestral lands since antiquity, and construction would damage sites of deep cultural and historic significance, including burial grounds.

A federal judge in September denied the tribe’s request for an injunction to block construction, but the tribe has continued to press the Army corps to withhold permits, which the builders need because the pipeline would cross a navigable waterway. The Sioux accuse the corps of being a rubber stamp for the oil industry, of ignoring its objections and of illegally issuing permits in violation of the Clean Water Act, the National Historic Preservation Act and other federal laws — charges that the corps denies.