A more than two-metre ocean sunfish rarely seen in Washington waters recently washed ashore on a beach at Cape Disappointment State Park near the mouth of the Columbia River.

It was found dead on the beach at low tide Aug. 27 by children after a campfire program, said June Mohler, a biological technician from Troutdale, Ore., working this summer as an interpretive assistant at the park.

"It's really an odd-looking fish," she said Friday.

"I knew what it was," she said. The mola sunfish is around, "but they're uncommon. Probably more likely in warmer waters."

Mohler estimated it weighed close to 136 kilograms.

There was no obvious cause of death. A few days later, it had washed back into the ocean, Mohler said.