Resin Birch, Swamp Birch: Betula glandulosa (Synonyms: Betula crenata, Betula glandulosa var. glandulosa) - Historically found occasionally along the lower Klickitat River as well as moist areas north and east of Larch Mountain, Multnomah County, OR.
Red Birch, River Birch, Spring Birch, Water Birch: Betula occidentalis (Synonyms: Betula beeniana, Betula fontinalis, Betula fontinalis var. inopina, Betula microphylla var. fontinalis, Betula microphylla var. fontinalis, Betula occidentalis var. inopina, Betula occidentalis var. occidentalis, Betula papyrifera ssp. occidentalis, Betula papyrifera) - Occasional along the lower Klickitat and Deschutes Rivers.
European Weeping Birch, European White Birch: Betula pendula (Synonym: Betula verrucosa) - Introduced from Europe and naturalized.
Bog Birch, Dwarf Birch, Swamp Birch: Betula pumila (Synonyms: Betula borealis, Betula glandulifera, Betula glandulosa var. glandulifera, Betula glandulosa var. hallii, Betula nana var. glandulifera, Betula pubescens ssp. borealis, Betula pumilahallii, Betula pumila var. glabra, Betula pumila var. glandulifera, Betula pumila var. renifolia) - Found in moist areas around Latourell Prairie, Multnomah County, OR.