Exxon Mobil Corp. will pay $1.05 million to settle federal violations for polluting the Yellowstone River in Montana in 2011, when a broken pipeline dumped 63,000 gallons of crude oil 150 miles downstream from Yellowstone National Park. A buried pipe, exposed during a drought, ruptured and allegedly caused the spill. Exxon previously paid nearly $135 million for cleanup and restoration and $14.6 million in other costs.