The raccoon of eastern Washington (_excelsus_) is a member of the Great Basin Fauna and has probably included southeastern Washington in its natural range for a long period of time. The raccoon has not extended its normal range into northeastern Washington, although it is seemingly ideal raccoon habitat; only an occasional vagrant occurs there. A stock of raccoons from which emigrants might come has existed in southeastern Washington and the Yakima Valley for some time. The Columbia River might serve as a highway by which emigrants could reach northeastern Washington. MARTES CAURINA.--The earlier distributional history of the western marten has been postulated by Davis (1939: 131-132), who stated: "When the ancestral stock split into the two groups, the one that gave rise to _americana_ may have pushed eastward across Canada to the Atlantic Coast; the other, giving rise to _caurina_, may have migrated southward along the Sierra Nevada-Cascade and Rocky mountains. Perhaps the great ice sheet was instrumental in pushing _americana_ eastward and separating it geographically from _caurina_." The present occurrence of _americana_ in Alaska and British Columbia is thought to have been by invasion from the east in postglacial time. Davis' theory seems basically correct but subject to correction in detail. The presence of _caurina_ in the southern Rocky Mountains suggests that it is not a Pacific Coastal species in the common sense. Had _americana_ occupied northern British Columbia in pre-Wisconsin Time, it and not _caurina_ would be expected to occur in the southern Rocky Mountains today, for the form found in British Columbia almost certainly would have been forced into the Rockies. The range now occupied by _caurina_ in the Rocky Mountains is so extensive as to suggest that martens could not have migrated into all of it from the Pacific Coast since Vashon Time, even had the region been unoccupied by any species of marten. The presence of _americana_ in Alaska and British Columbia suggests that it arrived in those areas before _caurina_ and that had the Rocky Mountains been unoccupied by martens in pre-Wisconsin time, _americana_ and not _caurina_ would have reached the Rockies first. It appears that _caurina_ occupied much of western North America in pre-Wisconsin Time and was forced southward into the southern Rocky Mountains and along the Pacific Coast by Vashon-Wisconsin ice. The separation of _americana_ and _caurina_ may be supposed to have occurred before the pre-Vashon-Wisconsin interglacial interval, perhaps by a glacier similar to but antedating the Vashon-Wisconsin glaciation.