We already noticed that Exxon/Mobil officials were downplaying the severity of that oil spill in the Yellowstone River. Now it turns out -- to absolutely no one's surprise -- that they were lying through their teeth:

Federal documents show it took Exxon Mobil nearly twice as long as it publicly disclosed to fully seal a pipeline that spilled roughly 1,000 barrels of crude oil into the Yellowstone River.

Details about the company's response to the Montana pipeline burst emerged late Tuesday as the Department of Transportation ordered the company bury the duct deeper beneath the riverbed, where it is buried 5 to 8 feet underground to deliver 40,000 barrels of oil a day to a refinery in Billings.

The federal agency's records indicate the pipeline was not fully shut down for 56 minutes after the break occurred Friday near Laurel. That's longer than the 30 minutes that company officials claimed Tuesday in a briefing with federal officials and Gov. Brian Schweitzer.

An Exxon Mobil spokesman said the longer time span was based on information provided to the agency by the company and the discrepancy might have come about because Exxon Mobil Pipeline Co. President Gary Pruessing was speaking without any notes in front of him when he addressed Schweitzer.