Sgt. Trent Crump said the woman was struck Thursday as she walked on BNSF Railway tracks near an intersection of three major streets.
According to Crump, the woman was struck by the first of two engines, fell between the rails but escaped being hit by the wheels.
Snow plows on the train reportedly forced the woman up under the train; it may have saved her life.
Crump said the woman was seriously injured and taken to a hospital where methamphetamine was found in her possession. Her identity was not released.
Crump said the engine's horn and the crossing signals were tested and working properly and that the woman's "inattention" apparently caused the accident.
Copyright 2015 The Associated Press modified.