"Witnesses said it was swimming around in the inlet in the morning, and then seemed to head directly for shore," said Brent Norberg with the National Marine Fisheries Service's Northwest Marine Mammal Stranding Network.

The property owner plans to tow the carcass into deep water and sink it, he said.

The whale died on a shell-covered mud bank Wednesday at Little Skookum Inlet near Shelton. A team of scientists went to the scene to conduct a necropsy - an animal autopsy - and collect samples. The examination was thwarted by high tide Wednesday and was completed Thursday.

The whale's body was covered with cuts from the shells, sustained in its death throes on the beach, but showed no other sign of external trauma. Clam and oyster shells and other debris were found in its mouth, and may have contributed to its death, said research biologist Robin Baird of the nonprofit Cascadia Research Collective in Olympia, who was at the site with state Department of Fish and Wildlife scientists.

"We don't have a cause of death yet," Baird said Friday. "But the animal was obviously very fresh. If there was anything unusual going on, we'll be able to tell."

Lab tests could take a few weeks, he said.

"The question is whether it went into the south Sound because it was sick, or blundered into the south Sound and got lost," Baird said.

The stranded whale was 22 feet 8 inches long - a female who had never had a pregnancy and was likely about 5 years old, he said. Minkes are sexually mature at about 7 years old, he said, when they average 28 feet. Adults of both genders are 30 to 33 feet long.

They're usually seen alone, and tend not to go near boats.

Area whale sightings over the past 10 days likely involved this whale, Baird said. Minkes have a relatively small dorsal fin, and this whale's fin was 14 to 16 inches high.

Minke whales are routinely seen round the San Juan Islands but rarely enter the south Sound. They are not listed as endangered, but little is known about their population numbers, Baird said. Fisheries service estimates for minkes off the West Coast suggest about 1,000 animals in that area.

Since 1930, 14 minkes have been reported stranded in the state - just three of them in the past 20 years and the most recent in 1990, in Totten Inlet, very close to this stranding.

Minkes are baleen whales, which include bowhead, humpback, sei, fin and right whales - among the largest mammals on the planet. They eat tiny marine creatures strained through baleen plates in their mouth. Baird said this whale had fish bones in its stomach, and did not appear to have starved.

The other class of whales is toothed whales, including sperm whales and the many varieties of beaked whales.

Orcas, also called killer whales, are actually a kind of dolphin.