A whale carcass washed ashore in Massachusetts on Thursday evening, officials said.

Cape Cod National Seashore Chief Ranger Leslie Reynolds said she first learned of the dead whale Thursday afternoon, around 2 p.m. At that time, it was floating about a half mile out from Nauset Light Beach.

"The life guards were watching it ... we have a lot of people on the beach this time of year," she said.

The whale washed ashore around 6:30 p.m. Reynolds went and took a look at the 40-foot female humpback, and said she saw no obvious signs of trauma.

The International Fund for Animal Welfare went and saw the whale Thursday afternoon while it was still in the water and it will be visiting the whale Friday to perform a necropsy, Reynolds said.

Seashore rangers will place warning signs around the whale and telling onlookers to stay away from the carcass.

While injured dolphins and seals often wash ashore, a whale this large is unusual, Reynolds said.

"This is the first I have experienced a large whale that has come ashore," she said. She's worked at the Cape Cod National Seashore the last five years.

The National Park Service said the plan is to let nature take its course after the necropsy.

"Typically they decompose on the spot, the birds come in and feed," Reynolds said.

She also noted the high tide Friday night might take part of the whale out to sea.