The developer of the stalled, $3.8 billion Dakota Access pipeline could get clearance from the Army as early as Wednesday to finish the project.
The Army says it will cancel further study and allow the four-state pipeline to cross under a Missouri River reservoir in North Dakota, the last big chunk of construction for the project to move North Dakota oil to Illinois.
The Standing Rock Sioux gets its drinking water from Lake Oahe and fears a pipeline leak would cause contamination. It has vowed to fight the Army permission in court.
It's unclear when pipeline developer Energy Transfer Partners would begin drilling after getting permission.
CEO Kelcy Warren has said the company should be able to finish the work in a little over three months once it has the go-ahead.