The King County medical examiner's office in Seattle says Olympic equestrian Amy Tryon, of Duvall, died of an accidental drug overdose.
The 42-year-old former firefighter died April 12.
KING-TV reports the medical examiner's report says she died of an acute combined opiate overdose, including Oxycodone.
Tryon rode for the U.S. Equestrian Team at the 2004 Athens Olympics and helped the U.S. team to a bronze medal. In 2008, she competed at the Beijing Olympics. Tryon also worked for Eastside Fire and Rescue.
The Seattle Times reported that in recent years Tryon suffered knee and back injuries that forced her to cut back on riding and focus on training horses.