Oil spill in creek originally underestimated, making it one of largest in North Dakota history

An oil pipeline spill that contaminated a tributary of the Little Missouri River last December is now estimated to be three times larger than originally thought, making it one of the most significant pipeline spills in North Dakota history.Belle Fourche Pipeline Co. reports about 12,615 barrels, or 529,830 gallons, of oil spilled as a result of a pipeline leak the company now believes started on Dec. 1 and was discovered by a landowner on Dec. 5, said spokeswoman Wendy Owen.The spill contaminated a hillside and Ash Coulee Creek about 16 miles northwest of Belfield.An earlier estimate put the spill at 4,200 barrels, or 176,400 gallons, but was revised after the company was able to pinpoint when the spill started and review metering data, said Owen.