KUOW's Ongoing Coverage Of The Deadly Oso Mudslide On Saturday, March 22, a mile-wide mudflow devastated Oso, Wash., 55 miles north of Seattle. The massive damage and mounting casualties have rocked the small community between Arlington and Darrington. Death Toll From Washington Mudslide Rises To 35 Published April 9, 2014 at 8:19 AM AKDT Twitter LinkedIn Email