A Shenandoah woman died this morning when her car collided head-on with a snowplow.An Iowa State Highway Patrolman says 59-year-old Patricia Milligan was eastbound on a county road near Essex when she must have seen the snowplow coming toward her. Milligan hit the breaks, then lost control and her car slid across the centerline, striking the snowplow head-on. The driver of the snowplow was not hurt.