If there is no mention of regions, the species occurs throughout the state.
Didelphis virginiana, Virginia Opossum. Wooded habitats. Widespread in W lowlands, local E; introduced from E U.S.
Sorex cinereus, Masked Shrew. Moist forested habitats. Cascades to coast and NE corner.
Sorex preblei, Preble's Shrew. Conifer forests. Blue Mountains in Garfield Co.; rare.
Sorex vagrans, Vagrant Shrew. Marshes, meadows, and moist forests.
Sorex monticolus, Montane Shrew. Forests. Cascades to coast, NE corner, and Blue Mountains.
Sorex palustris, Water Shrew. Mountain streams and pools. Olympics, Cascades, NE corner, and Blue Mountains.
Sorex bendirii, Pacific Water Shrew. Marshes and stream banks. W of Cascades.
Sorex trowbridgii, Trowbridge's Shrew. Forests. Cascades to coast.
Sorex merriami, Merriam's Shrew. Shrub steppe and grasslands. Columbia basin and foothills of Blue Mountains.
Sorex hoyi, Pygmy Shrew. Many habitats. NE corner (known only from S Stevens Co.), rare.
Neurotrichus gibbsii, Shrew-mole. Moist forests. Cascades to coast.
Scapanus townsendii, Townsend's Mole. Meadows. W lowlands.
Scapanus orarius, Coast Mole. Most habitats. W lowlands, central E Cascades slopes, and Blue Mountains foothills.
Vespertilionidae: Vespertilionid Bats
Myotis lucifugus, Little Brown Myotis. Roosts in buildings and caves.
Myotis yumanensis, Yuma Myotis. All habitats near water, roosting in trees, buildings, and caves.
Myotis keenii, Keen's Myotis. Forests, roosting in tree cavities and cliff crevices. Olympic Peninsula.
Myotis evotis, Long-eared Myotis. Conifer forests, roosting in tree cavities, caves, and buildings; also watercourses in arid regions.
Myotis thysanodes, Fringed Myotis. Dry open forests, roosting in caves, crevices, and buildings. E of Cascades, very local.
Myotis volans, Long-legged Myotis. Coniferous forests, also along watercourses in arid areas, roosting under tree bark and in rock crevices and buildings.
Myotis californicus, California Myotis. Most lowland habitats (near water in arid zones), roosting in buildings, rock crevices, and snags.
Myotis ciliolabrum, Western Small-footed Myotis. Open country, roosting in cliff crevices and caves. Columbia Basin.
Lasiurus cinereus, Hoary Bat. Forested areas, roosting among tree foliage. Might be found anywhere in migration.
Lasionycteris noctivagans, Silver-haired Bat. Forested areas, roosting under bark.
Pipistrellus hesperus, Western Pipistrel. Canyons in open country, roosting in rock crevices. E of Cascades along Columbia and Snake rivers.
Eptesicus fuscus, Big Brown Bat. All habitats, roosting in tree cavities, buildings, and rock crevices.
Euderma maculatum, Spotted Bat. Open country, probably roosting in cliff crevices. Okanogan, Douglas, and Grant counties, detected by vocalizations.
Plecotus townsendii, Western Big-eared Bat. All habitats, roosting in caves and mine shafts.
Antrozous pallidus, Pallid Bat. Open areas, roosting in rock crevices, caves, buildings, and trees. Columbia Basin.
Ochotona princeps, Pika. Talus slopes. Cascades and NE mountains.
Leporidae: Hares and Rabbits
Brachylagus idahoensis, Pygmy Rabbit. Shrub steppe. N Columbia Basin; virtually extirpated.
Sylvilagus floridanus, Eastern Cottontail. Meadows and open woodlands. Local in lowlands; introduced from E U.S.
Sylvilagus nuttallii, Nuttall's Cottontail. Shrub steppe. Columbia Basin.
Oryctolagus cuniculus, European Rabbit. Open meadows and forest edge. San Juan Islands; introduced from Europe.
Lepus americanus, Snowshoe Hare. Forests. Throughout except Columbia Basin.
Lepus townsendii, White-tailed Jackrabbit. Grasslands E of Cascades; much reduced in numbers.
Lepus californicus, Black-tailed Jackrabbit. Shrub steppe. Columbia Basin; reduced in numbers.
Aplodontidae: Mountain Beaver
Aplodontia rufa, Mountain Beaver. Forests and clearings. Cascades to coast.
Tamias minimus, Least Chipmunk. Shrub steppe. Columbia Basin.
Tamias amoenus, Yellow-pine Chipmunk. Sagebrush and dry conifer forests E of Cascades. Also subalpine zone in Olympics and Cascades.
Tamias townsendii, Townsend's Chipmunk. Wet forests from E slope of Cascades to coast.
Tamias ruficaudus, Red-tailed Chipmunk. Forests and meadows. NE mountains.
Marmota flaviventris, Yellow-bellied Marmot. Open rocky areas. E of Cascades.
Marmota caligata, Hoary Marmot. Subalpine and alpine zones. Cascades and far NE corner.
Marmota olympus, Olympic Marmot. Subalpine and alpine zones. Olympics.
Spermophilus mollis, Piute Ground Squirrel. Shrub steppe and grasslands. Lower Columbia Basin W of Columbia River.
Spermophilus washingtoni, Washington Ground Squirrel. Shrub steppe. Columbia Basin E of Columbia River; declining.
Spermophilus columbianus, Columbian Ground Squirrel. Mountain meadows and grasslands. North Cascades, N third and E edge of state.
Spermophilus beecheyi, California Ground Squirrel. Grasslands and oak woodlands. Puget Sound trough from Lewis County S, also E slope of Cascades from Kittitas County S; invaded from Oregon about 1912.
Spermophilus lateralis, Golden-mantled Ground Squirrel. Meadows and open woodlands. NE corner and Blue Mountains.
Spermophilus saturatus, Cascade Ground Squirrel. Meadows and open woodlands. Cascades.
Sciurus carolinensis, Eastern Gray Squirrel. Cities and towns. Puget Trough, Yakima Valley, and Spokane; introduced from E U.S.
Sciurus griseus, Western Gray Squirrel. Oak woodlands. Either side of Cascades from Pierce and Okanogan counties southward; populations much reduced.
Sciurus niger, Eastern Fox Squirrel. Cities and towns. Introduced from E North America and established in a few places in E lowlands; other introductions have not persisted.
Tamiasciurus hudsonicus, Red Squirrel. Conifer forests. From Lake Chelan E along N third of state and in Blue Mountains.
Tamiasciurus douglasii, Douglas' Squirrel. Conifer forests. Cascades to coast.
Glaucomys sabrinus, Northern Flying Squirrel. Forests. Throughout except Columbia Basin.
Geomyidae: Pocket Gophers
Thomomys talpoides, Northern Pocket Gopher. Open areas in all habitats. Cascades and E, down Columbia River to Clark County.
Thomomys mazama, Western Pocket Gopher. Meadows in forested areas. Olympics and lower Puget Sound S; many populations disappearing.
Heteromyidae: Heteromyid Rats
Perognathus parvus, Great Basin Pocket Mouse. Sandy shrub steppe. Columbia Basin.
Dipodomys ordii, Ord's Kangaroo Rat. Sandy shrub steppe. Tri-cities to Walla Walla.
Castor canadensis, Beaver. Wetlands.
Cricetidae: Cricetid Rats
Reithrodontomys megalotis, Western Harvest Mouse. Dense grass and marshes. Columbia Basin.
Peromyscus maniculatus, Deer Mouse. All habitats but much less common in wet forests inhabited by next species. .
Peromyscus keenii, Forest Deer Mouse. Forests. Cascades and W lowlands, often with preceding species. Formerly Peromyscus oreas, Columbia Mouse
Onychomys leucogaster, Northern Grasshopper Mouse. Sandy shrub steppe. Columbia Basin; declining.
Neotoma cinerea, Bushy-tailed Woodrat. Talus and rocky areas at all elevations.
Clethrionomys gapperi, Gapper's Red-backed Vole. Forests. Throughout except Columbia Basin.
Phenacomys intermedius, Heather Vole. Subalpine forest and meadows.
Microtus pennsylvanicus, Meadow Vole. Marshes and wet meadows. NE fourth.
Microtus montanus, Montane Vole. Grasslands and marshes. E of Cascades.
Microtus canicaudus. Gray-tailed Vole. Meadows and pastures. Clark Co.
Microtus townsendii, Townsend's Vole. Marshes, wet meadows, and riparian woodlands. W lowlands.
Microtus longicaudus, Long-tailed Vole. Moist habitats, lowlands and mountains. Throughout except Columbia Basin.
Microtus oregoni, Creeping Vole. Moist habitats. Cascades to coast.
Microtus richardsoni, Water Vole. Streams and wet meadows. Cascades and Blue Mountains.
Lemmiscus curtatus, Sagebrush Vole. Shrub steppe. Columbia Basin.
Ondatra zibethicus, Muskrat. Wetlands.
Synaptomys borealis, Northern Bog Lemming. Bogs and moist meadows. N Cascades, Okanogan Highlands, and Ne corner.
Muridae: Murid Rats
Rattus rattus, Black Rat. Most habitats, especially near habitations. Mostly W lowlands; introduced from Europe.
Rattus norvegicus, Norway Rat. Usually associated with humans. Introduced from Europe.
Mus musculus, House Mouse. Most habitats, especially near habitations. Introduced from Europe.
Zapodidae: Jumping Mice
Zapus princeps, Western Jumping Mouse. Forest clearings and meadows. NE and Blue Mountains.
Zaphus trinotatus, Pacific Jumping Mouse. Forest clearings and meadows. Cascades to coast.
Erethizontidae: New World Porcupines
Erethizon dorsatum, Porcupine. Open forest to shrub steppe.
Myocastor coypus, Nutria. Wetlands. Established locally both W and E of Cascades; introduced from South America.
Canis latrans, Coyote. All habitats.
Canis lupus, Gray Wolf. Forested habitats. N Cascades and NE corner, very rare.
Vulpes vulpes, Red Fox. Forests and woodlands. Mountains (native populations) and W lowlands (populations introduced from E U.S.).
Ursus americanus, Black Bear. Forested and semiopen areas.
Ursus arctos, Grizzly Bear. Forested and open areas. N border of state, very rare.
Procyon lotor, Raccoon. Wooded areas. W lowlands and along Columbia/Snake river systems.
Martes americana, Marten. Mountain forests, less common in lowlands. Throughout except Columbia Basin.
Martes pennanti, Fisher. Forests. Formerly Olympics, Cascades, and NE corner, now virtually extirpated.
Mustela erminea, Ermine. Forests. Throughout except Columbia Basin.
Mustela frenata, Long-tailed Weasel. All habitats.
Mustela vison, Mink. Wetlands. Throughout but rare in Columbia Basin.
Gulo gulo, Wolverine. Forests and meadows. Cascades and NE corner, very rare.
Taxidea taxus, Badger. Shrub steppe, grasslands, and open woodlands. E of Cascades.
Spilogale gracilis, Western Spotted Skunk. Woodlands and thickets. W lowlands and Blue Mountains foothills.
Mephitis mephitis, Striped Skunk. All habitats except sagebrush, more in open areas than preceding species.
Lontra canadensis, River Otter. Marine and freshwater. Throughout but only in large rivers E of Cascades.
Enhydra lutris, Sea Otter. Kelp beds. Outer coast of Clallam and Jefferson counties, formerly more widespread.
Puma concolor, Cougar. All habitats. Throughout except Columbia Basin.
Lynx canadensis, Lynx. Forests. Cascades and northeastern mountains, rare.
Lynx rufus, Bobcat. All habitats.
Otariidae: Eared Seals
Callorhinus ursinus, Northern Fur Seal. Pelagic. Offshore, mostly in spring.
Eumetopias jubatus, Northern Sea Lion. Marine, hauling out on rocks. Outer coast and San Juan Islands.
Zalophus californianus, California Sea Lion. Marine, hauling out on floating platforms. Winter visitor, mostly Puget Sound.
Phocidae: Hair Seals
Phoca vitulina, Harbor Seal. Marine, hauling out on rocks and sand islands. Entire coast.
Mirounga angustirostris, Northern Elephant Seal. Pelagic. Offshore, mostly in summer, rare.
* Species most likely to be seen.
Eschrichtiidae: Gray Whale
Eschrichtius robustus, Gray Whale*.
Balaenoptera physalus, Fin Whale.
Balaenoptera borealis, Sei Whale.
Balaenoptera acutorostrata, Minke Whale*.
Balaenoptera musculus, Blue Whale.
Megaptera novaeangliae, Humpback Whale* (offshore).
Balaenidae: Right Whales
Eubalaena japonica, North Pacific Right Whale.
Stenella coeruleoalba, Striped Dolphin.
Delphinus delphis, Common Dolphin.
Lagenorhynchus obliquidens, Pacific White-sided Dolphin* (offshore).
Grampus griseus, Grampus* (offshore).
Pseudorca crassidens, False Killer Whale.
Globicephala macrorhynchus, Short-finned Pilot Whale.
Orcinus orca, Killer Whale*.
Lissodelphis borealis, Northern Right-whale Dolphin.
Phocoena phocoena, Harbor Porpoise*.
Phocoenoides dalli, Dall's Porpoise*.
Ziphiidae: Beaked Whales
Berardius bairdii, Baird's Beaked Whale.
Ziphius cavirostris, Goose-beaked Whale.
Mesoplodon stejnegeri, Bering Sea Beaked Whale.
Mesoplodon carlhubbsi, Arch-beaked Whale.
Cervus elaphus, Elk. Forested regions. Olympics, migrating to lowlands in winter. Extirpated from E part but reintroduced in Cascades, Blue Mountains, and NE mountains and again established.
Odocoileus hemionus, Mule Deer. All habitats. "Black-tailed Deer" O. h. columbianus west of Cascades crest, sometimes wanders east.
Odocoileus virginianus, White-tailed Deer. Meadows and open forests. Two populations: NE corner and E edge; and lower Columbia River in Wahkiakum Co.
Alces alces, Moose. Forests with abundant wetlands. N Cascades and NE corner, rare.
Rangifer tarandus, Caribou. Forests. NE mountains, rare and perhaps extirpated.
Oreamnos americanus, Mountain Goat. Alpine and subalpine zone. Cascades; also introduced into Olympics.
Ovis canadensis, Bighorn Sheep. Open rocky areas in mountains. Formerly from Cascade crest E, entirely extirpated but reintroduced and established in Yakima County.
Information about distribution and habitats of land mammals from Terrestrial Mammals of Washington State, Location Data and Predicted Distributions, Washington State Gap Analysis Project Final Report, Vol. 3, by R. E. Johnson & K. M. Cassidy, 1997.