In this April 15, 2014 photo, an oil-tank train operated by Burlington Northern Santa Fe Corp., based in Fort Worth, Texas, cruises east alongside U.S. 10, a few miles outside of Staples, Minn. Multiple BNSF oil-tank trains travel through Staples every day, pulling about 110 tanks, sometimes more, of highly volatile crude from the Bakken shale fields in North Dakota to refineries east and south of Minnesota. (AP Photo/Mike Cronin)