When the giant old Douglas-firs yield to coastal storms, or disease, or just old age, the next generation has already begun. Deep in the shade under this forest canopy grows small Western Hemlock) trees. Where young Douglas-firs cannot become established, the hemlocks are happy. Because hemlock will ultimately succeed other species in this way, it is said to be a climax species. Western Hemlock will tolerate shade, but it does require considerable moisture, and a relatively rich organic layer.

Western Hemlock is generally assumed to be a lesser tree in stature than the great Douglas-firs, but specimens to three meters in diameter have been recorded. Normally, though, the tree is slim for its height, with the tallest trees, at about 75 meters, having diameters of only about one meter. Hemlock compensates by being prolific on a site, and often produces more timber than other species. Native peoples used various parts of the tree, but a dye made from the inner bark seems to have been most widely used.

For a large forest tree, Western Hemlock produces rather tiny cones, about the size of a cranberry. The needles, too, are small, and the branches have a lacy or feathery appearance. The top, or leader, of the tree droops to one side, an easy identifying mark.

Once a forest of Western Hemlock becomes established, it will sustain itself, until a natural disaster opens the forest floor again to the more fussy Douglas-fir.