One of the distinctive features of the winter landscape in the Pacific Northwest is the luxuriant growth of lichens, particularly noticeable on the deciduous trees and shrubs. Although many collections have been made in this region, little work has been done that would indicate the exact make-up of the lichen flora. This paper is a preliminary report on work that has been carried on during a period of years, and deals with a definite and rather natural area of Pacific Coast country. Numerous collections have been made, with the aim of learning more accurately the relative abundance and typical habitat of each species. The area included comprises roughly the upper (south) end of the broad Willamette Valley, together with numerous tributary valleys, and the adjacent mountain land. The rough mountain land is largely covered with coniferous forest. The low hills are often occupied by deciduous oak woods. Treeless areas are in pasture or under cultivation. The list here given furnishes: (1) A check list of the commonest lichens found in a definitely restricted area of western Oregon, and (2) brief notes on the usual habitat of each species listed. The project has been in part subsidized by grants from the General Research Council, Oregon State System of Higher Education.