Oregon Oak Quercus garryana

Oregon oak — also called Garry oak — is the only native oak in Washington and British Columbia, and one of the most ecologically important hardwoods in Oregon. It’s a deciduous tree that grows 30 to 80 feet tall depending on site conditions, with stout spreading branches and an open, rounded canopy. The deeply lobed leaves and thick furrowed bark make it easy to identify year-round.

Garry oak woodlands support some of the richest mycorrhizal communities in the PNW. The tree forms ectomycorrhizal partnerships with Boletus, chanterelles, Russula, truffles, and other fungal genera. Where Douglas-fir and oak overlap, the diversity of fruiting mushrooms can be outstanding — especially in fall.

Oregon oak is drought-tolerant and well-adapted to the wet-winter, dry-summer climate of the Willamette Valley, Puget Sound lowlands, and the rain shadow of Vancouver Island. It thrives on dry slopes, open prairies, and in the savanna woodlands that once covered huge swaths of the Pacific Northwest. These open woodlands historically coexisted with native grasses, wildflowers (including camas), and were maintained by Indigenous burning practices.

The range stretches from southern British Columbia through western Washington and Oregon into northern California. In Washington, look for it in the San Juan Islands, south Puget Sound prairies, and the Columbia River Gorge. In Oregon, the Willamette Valley, Umpqua Valley, and Rogue Valley all support significant oak populations. Wherever you find mature Oregon oak, check the ground beneath for boletes and chanterelles in fall.