Rain, Moss, and the Hoh

The rain begins as a suggestion, then becomes the weather. It falls in sheets and in individual drops that hang on the tips of hemlock needles before letting go. It is not a storm; it is a season that never quite decides to leave. In the Hoh River valley on the western side of the Olympic Peninsula, rain is the medium of the day, the substance in which everything green is bathed.

The valley is often counted the wettest in the lower forty-eight, and the title fits: moisture rolls off the Pacific, rises against the Olympic high country, cools, and falls. The mountains wring themselves out over the Hoh and its neighbors, sending streams down through canyons where the sound of moving water never stops. The forest beneath the peaks takes the rainfall and turns it into pigment.

Water in residence

Every surface in the Hoh is either wet, holding water, or decaying into water. The trails are dark and springy, roots exposed and polished by boots. Puddles lie in every hollow. Rain hangs from the smallest twig, beads on the back of a leaf, slides down trunks in clear streams. On no day of the year is the bark of a Sitka spruce entirely dry; the humidity alone keeps a film of moisture over everything.

The color of this valley is a thousand greens, from the black-green of the deep canopy to the pale yellow-green of a new fern fiddling itself open along the trail. Where sunlight cuts through, it lands in shafts of gold on beds of sorrel and moss. Where light never reaches, the forest keeps a green of its own, cool and patient, as if it had forgotten the idea of a dry day.

It is a forest that has no autumn of color, no dramatic turning. Instead it renews itself constantly, in layers. The old needles brown and drop; the ferns fold; the moss overlays the remains. The low trail by the river runs through a landscape that has been under construction for centuries and is nowhere near finished.

Moss with authority

Moss rules the Hoh. It hangs from the branches of bigleaf maples in long veils, giving the trees a look of age and concentration. It wraps the trunks of alder and spruce, covers the railings of boardwalks, pads the forest floor so evenly that the ground seems to have been carpeted. Nothing is too small to be claimed. The little ferns that grow out of the moss have their own moss, and the moss is thick enough to hold an entire miniature landscape.

The mosses are not one thing but many. Some grow upright in tight cushions. Some lie flat and feathery. Some hang in curtains and sway when the air moves. Together they soften every hard edge of the forest. A fallen log is not simply dead; it is a long green mound whose shape is only hinted at by a row of ferns growing out of the top of it. The word "tree" does not quite cover what a tree becomes here, because each tree is also a shelf of soil for everything that comes after.

Moss is not a parasite. It takes nothing from the tree it covers; it uses the bark merely as a place to stand, drinking moisture directly from the air. A bigleaf maple that looks about to be swallowed is not a sick tree but a small world, with rootless gardens hanging from every limb. The moss holds water long after the rain has paused, releasing it slowly in the afternoon fog, so the forest's green throat is never dry.

The rain is not lost on this green architecture. It drops from one layer to the next—from canopy to branch to trunk to fern to moss and finally to the deep duff, where it is stored and passed along slowly to the roots. By the time a drop reaches the river, it has touched most kinds of living tissue in the valley. That is why the Hoh is green even in the middle of winter.

Nurse logs and the patience of wood

The largest trees in the Hoh often stand in a peculiar way. At the base of a big Sitka spruce, the trunk seems to be in the air at first, supported by roots that arch down over something else. That something else is an older tree, felled long ago, now decomposing into a nurse log. The hemlock and spruce of the Hoh do not generally start on bare soil; they start on the body of the generation before them, taking root in the moss and rot of a fallen parent.

A nurse log is a water tank and a seedbed. In the wet temperate rainforest, the decay of a large trunk can take a century or more, and during that time it holds moisture through the driest weeks of summer and offers a stage above the dark floor for a seedling to catch light. When the old generation finally crumples into humus, the new trees are left standing in a perfect row, their roots straddling an empty corridor that was once a giant. The shape of the forest is, in this way, a record of loss.

Every nurse log is worth a pause. The top of one long-dead trunk can carry a row of hemlocks as old as a century, their trunks fused together at the base where they competed for the same small patch of rot. In the dim light, the raised roots look like fingers holding on to the memory of a tree.

The Hoh is a good place to witness that memory. The trails pass through groves where a line of upright hemlocks marks the skeleton of a fallen spruce, and along the floodplain, where the river moves gravel around, trees are less certain of their futures. The river and the forest exist in negotiation. A bank of alders may rise for fifty years, only to be undercut in one wet season and sent downstream as a tangle of roots.

What the rain sounds like

The forest is not quiet. The Hoh River runs beside the valley, a broad, glacier-fed current that turns gravelly riffles and deep green pools. Rain ticks on the big leaves of the maples and patters through the understory; the rhythm changes with every shift of wind. A winter wren opens its throat and brings the whole hush back into focus. When a branch gives way under the weight of water, the crack is followed by a long, soft settling of drops.

Elk use this valley, grazing the meadows at its edges and leaving tracks that fill with rain and cloud. Banana slugs cross the trail, orange against the dark duff, as if the ground itself had decided to move. The animals seem unhurried. There is no advantage in hurrying in a place where the weather has all the time in the world.

At night the rain is the loudest thing in the valley, a continuous hush over the river's lower note. The sound arrives from all sides and from above, as if the forest were breathing through water. By first light the path is dark again, the moss heavy, the air holding the particular expectation of a place that will not be dry before noon.

At the mouth of the river, the Hoh finally gives its collected water to the Pacific, and the cycle starts over. But up the valley, under the clouds, the rain remains the story. It is the author of the place—the reason for the moss, the patience of the nurse logs, the green that deepens year after year. The Hoh Rain Forest is what happens when water stays long enough to be architecture.

Olympic National Park

Photos: Sea Cow (CC BY-SA 4.0)