HAT ISLAND – Patti McClinchy still can’t believe she unearthed a fossilized molar belonging to a mammoth that roamed the frozen land at least 10,000 years ago.

She found the big barnacle-covered fossil, half buried on a rocky beach, while walking with her sister near their family’s summer cabin on the south point of the private island west of Everett.

At first McClinchy thought it was a petrified whalebone. When she learned that it was a mammoth tooth, she was bowled over.

“It’s so hard to comprehend,” said McClinchy, 50, a secretary at Henry M. Jackson High School in Mill Creek.

Her discovery is a reminder that during the most recent Ice Age, this slice of North America was a prime stomping ground for mammoths, the giant relatives of mastodons and modern elephants .

Scientists who study fossils and extinct life say mammoth remains are not rare in Washington.

Washington’s official fossil is the Columbian mammoth.

More than 40 documented major mammoth discoveries have been made in the state.

And massive Ice Age floods 12,000 to 15,000 years ago left fossils, in some cases entire mammoth skeletons, deposited in hillsides in the Yakima, Columbia and Walla Walla valleys, said George Last, a senior research scientist at the Department of Energy laboratory in Richland.

Still, there’s much to learn from their remains, said Daniel C. Fisher, a curator of the Museum of Paleontology and a professor of geological sciences at the University of Michigan.

“Specimens are potentially valuable scientifically, in understanding both the biology of these animals and the circumstances in which they lived,” he said.

Fisher recently returned from Siberia, where he examined the frozen, nearly intact carcass of a 4-month-old mammoth found by a reindeer herder.

It is believed to be the most complete mammoth carcass ever discovered, and Fisher hopes to take tusk and molar samples to determine the animal’s health, the changing fat content of its mother’s milk and variations in local air temperature during its lifetime.

When McClinchy found her own fossil on the beach, she took it to a science teacher at her school, who identified it as a mammoth tooth.

She said she would like to have the hoagie-sized molar examined by experts at the University of Washington’s Burke Museum of Natural History and Culture.

In the meantime, she’s looking for a display case to keep the fragile fossil in at her south Everett home.

McClinchy, who found the tooth last year, suspects it was worked lose from a bluff by rough winter storms.

Experts say most mammoth remains that are found date back to the late Pleistocene epoch, about 10,000 to 20,000 years ago. Continental ice sheets in the Northern Hemisphere, spanning Asia, Europe and North America, began receding at the time.

Scientists still debate why the behemoths, which were as large as modern Indian elephants, became extinct.

One leading theory pins the disappearance of the creatures on overhunting by humans. Others say it had more to do with climate change.

Reporter David Chircop: 425-339-3429 or dchircop@heraldnet.com.