Mountain hemlock is the tree of Mt. Hood’s snowy high country. In the western Oregon Cascades it forms the highest forest zone, the cold belt just below timberline, often in large pure stands. Look for a narrow, cone-shaped crown with a slender, drooping top, and short needles crowded all around the twigs.
This is a tree built for snow. Across its range, yearly snowfall can total tens of feet, and in places snow covers the ground for seven months or more. Seedlings and saplings simply bend under the weight and spring back upright after the melt. Growth is slow, the roots are shallow and wide-spreading, and individual trees can live more than 800 years. On the windiest ground near timberline it shrinks into low, shrubby krummholz.
Mountain hemlock shares the subalpine with Pacific silver fir, subalpine fir, Alaska-cedar and whitebark pine, over an understory of beargrass, big huckleberry and mountain heather. Its stands give wildlife hiding and thermal cover, and grouse eat its seeds. Fire is rare in these cool, wet forests, but when it comes it tends to kill most of the trees, and burned areas can take many decades to fill in again.
How to identify it
A narrow, cone-shaped evergreen with a limp, drooping top. Short, thick needles grow on all sides of the twig and curve upward, so branchlets do not lie flat. Cones are purple to brownish purple and roughly 1 to 3.5 inches long. Old trunks have thick bark broken into scaly plates.
Look-alikes
Western hemlock, common lower on the mountain, is the main look-alike. Mountain hemlock's cones are longer than those of other hemlocks, and its needles crowd all the way around the twig.
Habitat
Cold, snowy subalpine slopes with deep, long-lasting snowpack and loose, well-drained, acidic soils. It forms the highest forest zone in the western Oregon Cascades, reaching timberline, where it becomes shrubby krummholz. In southern Oregon it grows at about 5,200 to 7,500 feet.
Sightings in the forest
606 research-grade sightings in Mt. Hood National Forest on iNaturalist, most recently on October 15, 2026. See them on iNaturalist →