Mountain hemlock typically grows at subalpine elevations, to 40 m tall or less. The leader is erect or only slightly drooping. The branches droop but sweep upward at the tips. The leaves are similar to western hemlock in some ways; they are short (1-3 cm), flat, blunt, but they are bluish-green, of equal length, and densely cover the branches on all sides rather than being two-ranked. Stomata are equally distributed on upper and lower surfaces of the needles. The cones are longer (3-8 cm) than those of western hemlock and brown at maturity. Mountain hemlock typically occurs in sites with long winters and deep snowpacks, often occurring at timberline and in subalpine parklands.