Lasionycteris noctivagans.—Undifferentiated subspecifically from coast to coast, no basis is provided for judging the route by which this species entered the state.
Pipistrellus hesperus.—The northwestern periphery of the range of this bat, also, lies in eastern Washington.
Eptesicus fuscus.—Big brown bats from both eastern and western Washington seem to have been derived from the Pacific Coastal race of the species. Presumably it extended its range westward across the Cascades in early post-Pleistocene Time.
Lasiurus cinereus.—No speculation as to the distributional history of the hoary bat seems justified at present.
Corynorhinus rafinesquii.—The dark, coastal race of this bat probably persisted in southwestern Washington and western Oregon through Vashon Time and moved northward in the Recent. The paler intermedius probably invaded eastern Washington from eastern Oregon in the Recent.
Antrozous pallidus.—This species strays into eastern Washington from Oregon as part of the Great Basin Fauna.
Ursus americanus.—The dark, western race of the black bear (altifrontalis) and the paler, inland race (cinnamomum) were probably separated by a glacial divergence. The inland race has entered northeastern Washington in the Recent with other members of the Rocky Mountain Fauna.
Ursus chelan, etc.—The apparent past distribution of chelan indicates it to have invaded Washington from British Columbia since the Pleistocene.
The apparent absence of grizzly bears from the southern Cascades and western Washington may indicate their absence from these areas immediately before pre-Vashon time, or their extermination in or shortly after that period.
Procyon lotor.—The raccoon of western Washington seems to be the Pacific Coastal race which occurs also in western Oregon and northwestern California. This indicates that the coastal race (psora) was confined to the coastal area south of Washington during Vashon Time and has only recently reinvaded western Washington. It is possible, though less likely, that raccoons existed in southwestern Washington during Vashon Time but did not develop racial characters, or that the Columbia was crossed so frequently that genetic differences were dispersed throughout the entire population.