LAUREL, Montana -- An ExxonMobil pipeline that runs under the Yellowstone River ruptured and leaked hundreds of barrels of oil into the waterway, causing a 25-mile plume that fouled the riverbank and forced municipalities and irrigation districts downstream to close intakes, officials said Saturday.
The break near Billings in south-central Montana led to temporary evacuations of hundreds of residents along a 20-mile stretch. Cleanup crews deployed booms and absorbent material as the plume moved downstream.
The river has no dams on its way to its confluence with the Missouri River just across the Montana line in North Dakota. It was unclear how far the plume might travel.
"The parties responsible will restore the Yellowstone River," Gov. Brian Schweitzer said.
ExxonMobil spokeswoman Pam Malek said the pipe leaked an estimated 750 to 1,000 barrels of oil for about a half-hour before it was shut down.
"The timing couldn't be worse," said Steve Knecht, chief of operations for Montana Disaster and Emergency Services. "With the Yellowstone running at flood stage and all the debris, it makes it dang tough to get out there to do anything."
Brent Peters, fire chief for the city of Laurel about 12 miles east of Billings, said the rupture in the 12-inch-diameter pipe occurred late Friday about a mile south of Laurel.
He said about 140 people in the area were evacuated early Saturday due to concerns about possible explosions and the overpowering fumes. He said they were allowed to return at about 4 a.m.
In a statement, ExxonMobil said it was sending a team to help with cleanup, and that state and federal authorities had been alerted to the spill.
A 600-foot-long black smear of oil coated Jim Swanson's riverfront property just downstream from where the pipe broke.
"Whosever pipeline it is better be knocking on my door soon and explaining how they're going to clean it up," Swanson said as oil bubbled to the surface. "They say they've got it capped off. I'm not so sure."
Crews were putting out absorbent material along stretches of the river in Billings and near Laurel, but there were no attempts at capturing oil farther out in the river. In some areas oil flowed underneath booms and continued downstream.
The smell of oil permeated the air for miles downstream and through the city of Billings.
The cause of the rupture in the pipe carrying crude oil from Belfry to the company's refinery in Billings wasn't known.