Rocky Mountain Douglas-fir Blue Douglas-fir Inland Douglas-fir Colorado Douglas-fir

You know this tree from eastern Washington and Oregon forests, where its bluish-green needles and smaller cones distinguish it from the coastal Douglas-fir. This inland form grows taller, sometimes exceeding 130 feet, yet develops more slowly and tolerates colder, drier climates that would stress the coastal variety. The distinctive forked cone bracts remain diagnostic even when trees are young and lack striking appearance, and this feature separates Douglas-fir from all other PNW conifers.

Rocky Mountain Douglas-fir prefers moderate soil moisture and cooler sites; it cannot tolerate the hot, humid summers of Willamette Valley lowlands where coastal Douglas-fir excels. Plant it in eastern Washington sites or at elevation west of the Cascades. Laminated root rot, Swiss needle cast, and stem canker can severely check growth in the wet Cascades; this variety's strength lies in drier, colder sites where the blue-green foliage signals genetic adaptation to its native continental range.