True Firs Genus Abies — Pacific Northwest Species Guide

Grand fir (Abies grandis) showing characteristic flat needle arrangement in Pacific Northwest forest

True firs — genus Abies — are ectomycorrhizal trees of Pacific Northwest forests, from valley bottoms to timberline. Mushrooms of Cascadia names true firs among the hosts of several edibles: king boletes at higher elevations, the fib king (Boletus fibrillosus), matsutake in drier forest, Boletus subalpinus in high-elevation forest, several waxy caps (Hygrophorus), conifer chicken of the woods, and the morel Morchella snyderi in spring, mostly east of the Cascade crest (Siegel & Schwarz, Mushrooms of Cascadia).

Six Abies species occur in Washington and Oregon combined. Which one you are under depends on region and elevation, and for most of them field guides say only “true firs” rather than naming the species.

A note on Douglas fir: Despite the name, Douglas fir (Pseudotsuga menziesii) is not a true fir — it belongs to its own genus and is not covered here. It has its own page, linked below. True firs have upright cones that break apart on the branch rather than falling intact, and young bark that is smooth and gray with resin blisters.

True Fir Species of the Pacific Northwest

Six Abies species occur in Washington and Oregon combined. Elevation and range figures below come from the USFS Fire Effects Information System (FEIS).

Grand fir needles showing two distinct sizes and flat arrangement

Grand Fir

Abies grandis

Mostly a low-elevation valley tree west of the Cascades, where it is a minor part of wet coastal forests, and a moist-slope tree in the Cascades and northern Rockies. Flat needles in two distinct sizes. Field guides name it as a host of the toxic red-pored bolete (Rubroboletus pulcherrimus), and its decay fungi include Indian paint fungus and Armillaria ostoyae (FEIS); see the full profile.

Westside Eastside Mycorrhizal Host
Full species profile →
Pacific silver fir needles showing white undersides and forward-pointing top needles

Pacific Silver Fir

Abies amabilis

A fir of the Cascade Range of Washington and Oregon and the Olympic Mountains, ranging north to Alaska and south to northwestern California. Needles are glossy green on top and silvery white underneath, spreading horizontally or brushed forward. Young bark has resin blisters; older bark is rough and flaky (FEIS).

Westside Mycorrhizal Host
Noble fir showing blue-green needles and distinctive large cone with elephant-head bracts

Noble Fir

Abies procera

A Cascade Range fir from Stevens Pass, Washington, south through Oregon, with scattered populations in the northern Oregon Coast Range and the Willapa Hills. The upright cones are large, generally 11 to 18 inches long (FEIS). MycoMatch lists the Cascade chanterelle (Cantharellus cascadensis) with noble fir.

Westside Mycorrhizal Host
Subalpine fir with characteristic narrow spire shape at timberline

Subalpine Fir

Abies lasiocarpa

The fir of the high Olympics, Cascades, and Rockies. In the Olympics and Cascades it is generally found between 4,000 and 6,000 feet, and it reaches timberline as flagged and mat-like (krummholz) trees (FEIS).

Subalpine Mycorrhizal Host
White fir with long blue-gray needles in a high-elevation forest

White Fir

Abies concolor

In Oregon it grows in the Blue Mountains and the southern Cascades; in the Cascades the white fir zone lies above about 4,900 feet (FEIS). More prevalent in the southern part of the region.

Eastside Mycorrhizal Host
California red fir with reddish-brown bark in a high-elevation Sierra Nevada forest

California Red Fir

Abies magnifica

Primarily a Sierra Nevada and northern California species, reaching the southern Cascade Range of Oregon (FEIS). Mature bark is thick and fissured, and the upright cones can reach 9 inches.

Subalpine Mycorrhizal Host

How to Identify True Firs

True firs share a few field marks. Cones grow upright on the upper branches and break apart in place, so intact cones are not found on the ground. Needles attach directly to the twig with no woody peg, unlike spruce. Young bark is smooth and gray with resin blisters, and it becomes rougher and more furrowed with age.

To tell the species apart, look at where the needles are white (top, bottom, or both surfaces), how the needles are arranged on the twig, and the shape of the tree. Region and elevation help too: grand fir is mostly a low-elevation valley tree west of the Cascades, while subalpine fir reaches timberline (FEIS).

Time Your Hunts in Fir Forests

Layer soil temperature, precipitation, and burn perimeter data on Forayz to find when conditions are right for chanterelles and king boletes in true fir habitat.

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Also on iOS: ForayzU

Practice identifying Pacific Northwest trees and mushrooms with spaced-repetition flashcards — including a dedicated tree identification deck.

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Sources: Mushrooms of Cascadia (Siegel & Schwarz, 2024); MycoMatch (© Ian Gibson), a compilation of published descriptions through which most other field-guide authors named here are quoted.

Related Resources

Photos: True Firs — Lauren Bosch (CC0) · Grand fir needles — Lauren Bosch (CC0) · Pacific silver fir needles — Shane Johnson (CC0) · Noble fir — Michael Bunsen (CC0) · Subalpine fir — Shane Johnson (CC0) · White fir — Alex Heyman (CC0) · California red fir — rockybajada (CC0).

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