Last weekend, an oil pipeline under the Yellowstone River in Montana broke, unloading more than 1,000 barrels of crude oil into the river. The cause of the break is unknown, however some officials think it may be due to unusually high river levels thanks to the spring snow melt. This high water has made containment of the spilled oil very difficult. The effects of the spill are yet to be determined, but traces of the spill have been discovered 30 miles down-river, so far.