Pendleton wildlife biologists found the olive ridley sea turtle on Blue Beach. Park spokeswoman Kelly Terry says the 42-pound turtle had shell wounds and was dehydrated, underweight and hypothermic. It was taken to SeaWorld for care.
Veterinarians said the turtle had ingested plastic trash. Plastic bags are often mistaken for jellyfish, which the turtles feed on.
The turtle is being treated with fluids and antibiotics and officials hope to be able to return it to the wild this summer.
The olive ridley sea turtle species breeds along the coast of Mexico and is considered endangered.
The Associated Press contributed to this report.