Lava Canyon is one of the most dramatic hikes on the south side of Mount St. Helens, where volcanic history, rushing water, and sheer rock walls come together in one unforgettable landscape. This striking canyon was shaped by lava flows and later scoured by the powerful forces unleashed during the 1980 eruption, leaving behind a rugged corridor of cliffs, waterfalls, and exposed canyon walls that feels both wild and otherworldly.
The experience begins at the Lava Canyon Interpretive Site, where the first section of trail offers an easy, paved, ADA-accessible walk into the canyon. This opening stretch is ideal for families, casual visitors, and anyone wanting a close-up look at the geology without committing to a strenuous hike. Along the way, interpretive signs help tell the story of how this landscape was formed, while viewpoints reveal the Muddy River cutting through basalt and ancient lava rock.
Beyond the paved section, Lava Canyon becomes more adventurous. The trail drops deeper into the canyon, with steeper grades, narrower tread, and dramatic views of waterfalls and churning water below. Under normal conditions, this area is known for its suspension bridge and thrilling canyon scenery, but the Forest Service currently notes that the suspension bridge is closed due to cable damage, so the old 1.4-mile upper loop is not possible right now. Visitors can still explore both sides of the river where open, but should expect to return the way they came rather than complete the full loop.
This is a trail that rewards respect and preparation. The Forest Service warns visitors to stay on the trail at all times, noting that going off trail is dangerous and that fatalities have occurred in the canyon area. Fast-moving water, steep drop-offs, and exposed sections make Lava Canyon a place to slow down, take in the views, and use caution every step of the way. Pets are allowed only on leash, and a Northwest Forest Pass, Digital Day Pass, or Interagency Pass is required for parking.
Whether you stop for the accessible interpretive walk or continue farther into the canyon for a more rugged experience, Lava Canyon offers one of the most visually powerful trail experiences in the Mount St. Helens region. It is a place where the mountain’s story is written into the stone, the water, and the shape of the land itself.
Trail details: Lava Canyon Trail #184, near Cougar, Washington. Trailhead coordinates: 46.1654, -122.0889.
Getting there: From I-5, take Exit 21 and head east on SR 503 toward Cougar. Continue through Cougar on Lewis River Road / Forest Road 90 past Swift Reservoir, then turn left onto Forest Road 83 and follow it to the Lava Canyon trailhead.
Call to action: Add Lava Canyon to your Mount St. Helens itinerary for a hike that combines volcanic geology, canyon drama, and some of the most memorable waterfall views on the mountain’s south side.
Current seasonal note: As of April 1, 2026, the Lava Canyon area is still under snow and Forest Road 83 is gated at Marble Mountain Sno-Park, so vehicle access to the trailhead remains closed for the season.