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Twin Falls Natural Area — March 2006

By Holly Zox

Before the freeway, before the houses, or loggers, the Snoqualmie River and the increased moisture and light in its riparian zone would have been an island of diversity within a sea of forest. Ironically, the river at Twin Falls Natural Area, nestled in between I-90 and the Iron Horse Trail east of North Bend protects a narrow swath of old forest in a sea of clear-cuts and development. The large “island” of the protected Cedar River Watershed to the south could be a source of biota for whoever dares live so close to the freeway in this lovely old fragment. The trail to the falls is mitigation for an underground hydroelectric project. The trail begins in mature second growth Douglas-fir (Pseudotsuga menziesii) forest beside the South Fork Snoqualmie River. Wind and the roar of the river cannot muffle the drone of the interstate. Herbrobert (Geranium robertianum) and Bohemian knotweed (Polygonum x bohemicum) are further reminders of how people have disturbed this “natural area.” Nonetheless, the forest is magnificent, and well-loved by critters with two, four, six, or more legs.

Ninety-one inches of rain in an average year supports a luxuriant coating of epiphytes. Ferny bigleaf maples (Acer macrophyllum) spread mossy arms overhead as the trail rolls gently by the river. The deciduous layers send new leaves to greet the lengthening spring days. Skunk-cabbage (Lysichiton americanum) blooms in a low wet area, surrounded by Sitka spruce (Picea sitchensis), salmonberry (Rubus spectabilis), and western redcedar (Thuja plicata). Scouring-rush (Equisetum hyemale) duels with salmonberry under a grove of red alder (Alnus rubra). A Sitka spruce straddling the memory of its nurse log catches the light and ultimately the racket of the freeway fades as the green glow takes over.

Now the grade steepens as the trail climbs above the river. Firescarred snags and furrowed Douglas-firs shade an evergreen understory of sword fern (Polystichicum munitum) and low Oregon-grape (Berberis nervosa). Keep an eye out for rattlesnakeplantain (Goodyera oblongifolia). Young western hemlock (Tsuga heterophylla) and western redcedar wait to dominate the next stage of this “young” old growth forest. Sturdy benches perched atop a high point across from the falls invite snacking and reflection, but the oldest trees are still to come.

The trail descends, open and deciduous again. A fence and plaque herald an “Old Growth Tree.” Stand under a younger hemlock and admire a still younger hemlock growing out of the side of the ancient Douglas-fir. Large old Sitka spruce and unfenced Douglas-firs accompany as the trail climbs up a wet hill with maidenhair fern (Adiantum aleuticum) and Scouler’s corydalis (Corydalis scouleri). Exposed glacial till, clay, and sand layers of the moraine next to the freeway are soon broken by rock outcrops. Stairs with handrails lead down to a viewing platform for the lower falls. Back up on the trail, a big bridge straddles the falls. Look up to the stair-stepped upper falls, down over the precipice of the lower falls, at huge chunks of rock in the gorge, then scan the canyon walls for maidenhair spleenwort (Asplenium trichomanes). Freeways are only one way to move matter.

The bridge makes a good turn-around for this easy 2.5 mile roundtrip hike. Wear sturdy boots and bring rain gear. Directions: take exit 34 from I-90 (Edgewick Road). Turn south on 468th Ave SE and drive ½ mile to 159th St just before the bridge over the river. The trailhead and parking ( $5 state park day use fee) are in ½ mile at the road’s end.

Updated: July 3, 2016
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