Discover 6 Extinct Animals That Lived in Washington

Written by Jeremiah Wright
Published: July 21, 2022
Share on:


Washington is located in the Pacific Northwest region of North America. This state is distinguished for its dry summers and wet, mild winters. As of the latest report, Washington is the 13th most populous state in the United States, with more than 7.8 million people. Many of these people enjoy the abundance of prairies, wetlands, estuaries, rainforests, shrubsteppes, marine waters, and grasslands.

Because of its rich forests and vibrant marine ecosystem, Washington became a home for thousands of species of animals. Some continuously thrive, and others are in grave threat due to toxic marine contaminants. Unfortunately, some species are extinct today. These majestic creatures may be extinct, but their memories live on in our museums today.

Here are six extinct animals in Washington:

1. Tacoma Pocket Gopher

Tacoma Pocket Gopher
SpeciesThomomys mazama
Sub-speciesTacoma Pocket Gopher (Thomomys mazama tacomensis)
Extinct since1970

The Tacoma Pocket Gopher, scientifically named Thomomys mazama tacomensis, is a subspecies of Mazama pocket gopher (Thomomys mazama). They belong to the largest order of mammals, which are rodents. The first recorded specimen of the Tacoma Pocket Gopher was collected in 1853 by Suckley and Cooper. According to Walter Taylor in his biological survey in 1919, this sub-species looked darker than other species of pocket gopher in Western Washington, lacking the irregular white areas observable in other species. Its nasal area was narrower anteriorly. The U.S. Fish and Wildlife Service reports delisting this sub-species from the endangered species list because it is already extinct due to habitat loss due to intense urban development.

2. Diatryma


The diatryma is a giant flightless bird that can grow up to 6.5 to 7 feet.


SpeciesGastornis gigantea
Extinct since56 – 45 million years ago

The diatryma, scientifically called Gastornis gigantea, is a giant flightless bird that can grow up to 6.5 to 7 feet (198 to 213 cm), according to recorded specimens. They have enormous heads, tiny wings, chunky bodies, and elephant-like legs. They are believed to have powerful bites, but scientists have divided opinions about their diets. Most scientists think they are fast runners that feed on smaller mammals. However, research shows that some scientists think otherwise. They lack sharp claws that are more common with carnivores, and their stout bodies suggest they were not suited for fast movements.

According to records, the first Diatryma fossil was found in New Mexico, USA. There were also pieces of evidence found in Wyoming, Washington, and several local parts of Europe.

3. Tonsala Hildegarde Olson

Tonsala hildegardae holotype

Tonsala Hildegarde Olson is a species that came from Plotopteridae.

©Smithsonian Institution, NMNH, Palentology / CC0 1.0 – License

Tonsala Hildegarde Olson
SpeciesTonsala Olson
Extinct from33.9 million to 23 million years ago

Tonsala Hildegarde Olson is a species that came from Plotopteridae, which is an extinct family of flightless seabirds from the Oligocene of Washington. Hildegarde Howard discovered the first recorded specimen of Tonsala in 1969. In 1980, Storrs Olson discovered another holotype in Washington. According to Olson’s studies, the specimens found in Washington are wing-propelled birds with a paddle-like forelimb, suggesting that they have convergent similarities to penguins.

4. Columbian Mammoths

Columbian Mammoths

Columbian mammoths are the largest mammoth species.


Columbian Mammoths
SpeciesMammuthus columbi
Extinct sinceEarly Holocene – 11,000 years ago

The Columbian mammoths were hybrid species that were considered cousins of woolly mammoths. They roamed North America during the Pleistocene epoch. The key distinction between Columbian mammoths (Mammuthus columbi) and woolly mammoths (Mammuthus Primigenius) was that Columbian mammoths had less fur. Columbian mammoths are the largest mammoth species; they can grow up to 13 feet and weigh up to 22,000 pounds.

The first Columbian mammoth fossil in Washington was discovered in Wena’s Creek, near Selah, central Washington State. A left humerus was found while constructing a private road in 2005. The Columbian mammoth is Washington’s state fossil.

5. Sea-Tac Giant Sloth

Megatherium americanum Skeleton

The Sea-Tac giant sloth is a giant carnivorous sloth that once roamed in the late Pleistocene of Washington.

©Ballista / CC BY-SA 3.0 – License

Sea-Tac Giant Sloth
SpeciesMegatherium americanum
Extinct since10,000 years ago

Sea-Tac giant sloth, scientifically named Megatherium americanum, is a giant carnivorous sloth that once roamed in the late Pleistocene of Washington. The very first specimen was discovered at Seattle-Tac Airport in 1961. Four workers uncovered a bone that was 45 inches long. The animal stood 11 feet tall and lived more than 10,000 years ago. During its initial discovery, scientists thought it was an Ice Age bison. Washington geologist Howard Coombs thought the bones were preserved perfectly and were in remarkable condition. However, the specimen needed further reconstruction and new bones manufactured. In 1977, scientists realized it was a giant sloth. Modern sloths are herbivores that feed on leaves, buds, and fruits. They initially considered giant sloths to feed on tree foliage. However, prehistoric giant sloths’ diets were far from those modern herbivore sloths.

There have been many theories about the diet of Megatherium americanum. Some scientists thought they were carnivores. Further studies were written by Susana Bargo in 2001, analyzing the jaw of the specimen found in Seattle-Tac airport and its functions. Megatherium americanum has triangular, sharp-edged teeth, high or deep crowns, short roots, and two fused ridges. Bargo states, “This suggests that giant sloths used their teeth mainly for cutting, rather than grinding. Hard and fibrous food was not the main dietary component.” Bargo suggests that they were opportunistic carrion-feeders.

6. Mastodon

Illustration of a Mastodon on a white background

Mastodon refers to any species from the Mammut genus.

©Liliya Butenko/

SpeciesMastodon americanum 
Mastodon cosoensis
Mastodon matthewi 
Mastodon pacificus
Mastodon raki Frick
Extinct since11,000 years ago

Mastodon refers to any species from the Mammut genus. At first glance, a mastodon may look like a mammoth. Both of these animals have tusks, but the mastodon had bigger ones even though their bodies were much smaller than a mammoth. Mastodon and mammoth came from the same order as elephants, Proboscidea, but their families differed. There are several key differences between these animals that distinguish them.

Mastodon americanum is the most common of several species of Mastodon. Two specimens of M. americanum found in Washington have been recorded by Oliver Hay, an American paleontologist.

The photo featured at the top of this post is © Liliya Butenko/

Share on:
About the Author

I hold seven years of professional experience in the content world, focusing on nature, and wildlife. Asides from writing, I enjoy surfing the internet and listening to music.

Thank you for reading! Have some feedback for us? Contact the AZ Animals editorial team.