Oil mixed with water from an oil spill along the Yellowstone River is pictured in Laurel Montana
Oil mixed with water from an oil spill along the Yellowstone River is pictured in Laurel, Montana, July 5, 2011. An Exxon Mobil pipeline ruptured on Friday night about 150 miles downstream from Yellowstone National Park near the town of Laurel, Montana, just southwest of Billings, dumping up to 1,000 barrels, or 42,000 gallons, of crude oil into the flood-swollen river. REUTERS/John Warner (UNITED STATES - Tags: DISASTER ENERGY)