Ruth Pennington Trillium Trail Loop Hike Nature Trail Tryon Creek State Natural Area Portland Oregon

Want to learn about the native plants growing in Tryon Creek State Natural Area and elsewhere in the forests around Portland? Take an easy stroll (or roll a wheelchair) around Trillium Trail. This pair of paved loops is located next to Tryon Creek Nature Center and totals just 0.37 miles in length. Markers identify the green things growing along the trail and viewing decks peer into different layers of the forest to add insights to Trillium Trail.

Find the start of Trillium Trail on the south side of Tryon Creek Nature Center next to the parking area and a curved stone bench. Trillium Trail is just to the left of Old Main Trail, which ventures father south for a longer loop through Tryon Creek State Natural Area. A kiosk at the trailhead explains how native plants are critical for healthy forests.

The forest surrounding the Trillium Trail hasn’t always looked this lush and healthy. Invasive species, like English ivy, had taken over and made it difficult for native plants to grow. Thanks to volunteers who removed the ivy, the native plants are now flourishing. Native plants filter water and keep it cool, clear, and clean, three essential elements to maintaining a healthy watershed.

Markers along Trillium Trail identify a wide variety of native trees, shrubs, and ground-covering plants, like baneberry, bigleaf maple, common snowberry, Douglas fir, evergreen huckleberry, fairy lantern, Hooker’s fairybells, Indian plum, inside-out flower, lady fern, Pacific dogwood, red elderberry, red huckleberry, stinging nettle, sweet coltsfoot, western red cedar, western trillium, wild ginger, and wood fern.

Walk up the paved trail for less than 100 yards to a marked split. The upper loop on Trillium Trail begins to the left. Both loops are quite short and easy to connect. Walking along the upper loop, you may notice a thin layer of moss growing over the trail, giving the illusion that you are following a green carpet through the forest. In addition to the markers naming different plants, you’ll find several covered panels along Trillium Trail. Flip open the wooden top to learn more about the forest. Expose the first panel on the upper loop to learn about banana slugs:

What is yellow and tan with dark splotches all over and looks like a ripe banana? The banana slug! This inhabitant of Tryon Creek is most often seen in the wet, warm times of fall and spring. During the dry, warn weather, slugs go into torpor (a period of inactivity). In the winter, they hibernate.

Trillium Trail Tryon Creek
Learn about banana slugs on Trillium Trail

Another waiting-to-be-revealed panel explains how deer adapt for the winter by growing thicker coats with hollow hair for increased insulation. Deer also bulk up with added body fat around organs and beneath their skin. Other panels on Trillium Trail have primers on lichens and mushrooms, and one explains why leaves change color in the autumn.

Trillium Trail Bench Tryon Creek
A bench on Trillium Trail

The upper and lower loops each have viewing decks that lead out over a hillside for a look into the understory of the forest.

Leave the first viewing deck and walk past one of the loop’s many benches to come to a junction with the lower loop, just 0.18 miles from the start. If you turned right, you could walk straight back to the trailhead. Instead, turn left onto the lower loop to walk through more forest.

Much like the upper loop, the second loop has markers for plants and a viewing deck that takes the trail out to a hillside perch.

Trillium Trail Viewing Deck
The viewing deck on the Lower Loop of Trillium Trail

When the lower loop concludes, make two left turns to head back to the nature center, completing an easy 0.37-mile long trail with a mere 15 feet of elevation change.

Leashed dogs are welcome on Trillium Trail, but bikes are not allowed. Trillium Trail’s more formal name is Ruth Pennington Trillium Trail, named after a champion for Tryon Creek’s preservation who helped create Trillium Trail. No permit is needed for Trillium Trail, which is an ADA nature trail. Parking at the trailhead is free, so an Oregon State Park’s pass is not required.

Trillium Trail Loop
The lower loop of Trillium Trail

To get to the trailhead: From Portland, take Interstate 5 south to exit 297 for Terwilliger Boulevard. At the end of the ramp, you will merge onto SW Barbur Boulevard and come to an intersection with SW Terwilliger Boulevard. Turn right, drive 2.4 miles down SW Terwilliger Boulevard, and turn right into the main entrance for Tryon Creek State Natural Area. Find parking in the lots in front of the nature center.

Trailhead address: 11321 SW Terwilliger Boulevard, Portland, OR 97219
Trailhead coordinates: 45.4411, -122.6759 (45° 26′ 27.95″N 122° 40′ 33.23″W)

Elevation Profile
Click or hover over any spot on this elevation profile to see the distance from the start and elevation above sea level at that location, which will be highlighted on the map.
Trail Map

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These photos were taken in January of 2017. Click to enlarge.
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