Overview
Lava Canyon is unlike any other trail in the Pacific Northwest. When Mount St. Helens erupted on May 18, 1980, massive mudflows (lahars) raced down the Muddy River, stripping away centuries of soil and vegetation and exposing an ancient volcanic gorge that had been hidden beneath the forest floor. The result is a geological wonder: polished basalt walls, columnar rock formations, and waterfalls pouring through lava tubes and narrow slots that no one had seen in recorded history.
The 6.5-mile loop drops into this gorge, crosses a suspension bridge, scrambles along exposed rock ledges, and climbs back out through recovering forest. With 1,500 feet of elevation change, several exposed sections, and a metal ladder bolted to a cliff face, this is a genuine adventure. It's not a trail for everyone, and that's part of what makes it special. It's a very different kind of day than the alpine meadow hikes in the southern part of the forest, like the Indian Heaven Wilderness Loop or the Goat Ridge Trail.
Dogs are not allowed on this trail due to the exposed scramble sections and ladder. This is not a recommendation; it's a hard rule for good reason. The terrain is too hazardous for four-legged companions.
Getting to the Trailhead
From Portland, take I-5 north to Woodland (exit 21) and follow SR-503 east. Continue past Cougar and turn left onto Forest Road 83, following signs for Lava Canyon. The trailhead is at the end of Forest Road 83, roughly 70 miles and 2 hours from Portland.
From Randle (on US-12), head south on Forest Road 25, then turn west onto Forest Road 83. This approach is about 40 miles from Randle and takes roughly 1 hour and 15 minutes.
The trailhead has a moderate-sized gravel parking lot (approximately 25 spaces), a vault toilet, and an interpretive sign explaining the geological history. A Northwest Forest Pass is required ($5/day or $30/year). The lot fills on summer weekends, so arrive before 9 AM for guaranteed parking.
Forest Road 83 is paved but narrow, with some potholes after spring snowmelt. It's accessible to passenger cars, though low-slung vehicles should take it slow.
The Route
The trail can be hiked as a 6.5-mile loop (clockwise is recommended) or shortened to a 1.4-mile out-and-back along the upper paved section only. The full loop is described here.
Upper Trail: Trailhead to the Gorge Rim (0.0 to 0.7 miles)
The trail begins on a paved, ADA-accessible path with interpretive signs. This first section follows the rim of the canyon, offering dramatic views down into the gorge without any technical difficulty. You'll see the Muddy River flowing through polished lava rock about 100 feet below, and the contrast between the bare volcanic walls and the slowly returning vegetation is striking.
At 0.7 miles, the paved path ends at a viewpoint overlooking a waterfall. This is the turnaround point for the easy option. If you continue past the "End of Maintained Trail" sign, the character of the hike changes completely.
Descent into the Gorge (0.7 to 2.0 miles)
Past the maintained section, the trail drops steeply into the canyon on a series of rough steps and narrow rock ledges. There are cable handrails bolted into the rock at the most exposed points. The footing is uneven, and the rock is frequently wet from spray. Take your time here.
At around 1.2 miles, you'll reach the suspension bridge spanning the Muddy River. The bridge is solid but narrow (single-file only) and sits about 60 feet above the river. Looking upstream from the bridge, you can see a 100-foot waterfall pouring through a narrow slot in the basalt. This is one of the most dramatic views on any trail in Washington State.
Below the bridge, the river has carved the rock into smooth, flowing shapes that look almost sculpted. The stone ranges from dark basalt to lighter pumice layers, and the geological record of multiple eruptions is visible in the cross-section of the canyon walls.
The Lower Loop and Ladder Section (2.0 to 4.0 miles)
After crossing the bridge, the trail follows the river downstream through the deepest part of the gorge. This is the most challenging section. The path alternates between rocky scrambles, narrow ledges, and packed dirt through recovering alder forest.
At roughly 2.5 miles, you'll encounter the ladder. A 30-foot metal ladder is bolted to a near-vertical basalt wall, descending to a lower section of the canyon. The rungs are solid and there's a cable handhold, but this is genuinely exposed. If you're uncomfortable with heights or have limited upper body mobility, this section is a deal-breaker. There is no bypass.
Below the ladder, the trail continues along the river through a landscape that looks almost alien. Smooth lava flows, twisted columns of basalt, and stranded boulders the size of cars line the riverbed. In several places, you can see where the 1980 mudflow scoured the rock clean, leaving a polished surface that contrasts sharply with the rougher, older formations.
Multiple small waterfalls and cascades appear along this section, some dropping through crevices in the rock that weren't visible before the eruption stripped the overlying soil.
Climb Out and Return (4.0 to 6.5 miles)
The trail begins climbing out of the gorge around the 4-mile mark, ascending through young forest on the south side of the canyon. This section gains about 800 feet over 1.5 miles on a series of switchbacks. The forest here is mostly alder, vine maple, and young Douglas fir, all of which colonized the hillside after the 1980 eruption. It's a living example of ecological succession, and the difference between this recovering forest and the old-growth elsewhere in Gifford Pinchot is stark.
Near the top of the climb, you'll reach a junction with a connector trail that leads back to the trailhead area along a ridgeline. The final mile is relatively flat and passes through thinning forest with views south toward the Lewis River valley. Total loop time for most hikers is 4 to 6 hours.
Difficulty and Hazards
This trail earns its moderate-hard rating. The upper paved section is easy, but the full loop includes:
- Steep, exposed descents with cable handrails on wet rock
- A 30-foot metal ladder on a near-vertical cliff (no bypass option)
- Narrow ledges with drop-offs above the river
- Uneven, rocky footing throughout the gorge section
- Stream crossings that may be tricky during high water (June)
This is not a good trail for anyone with a fear of heights, limited mobility, or young children. The ladder section alone disqualifies it for most families with kids under 12. There have been injuries on this trail from falls on wet rock, so respect the conditions and turn around if anything feels beyond your ability.
Trail Conditions by Season
June: The trail opens once Forest Road 83 is clear of snow, usually by mid-June. Early season means high water in the Muddy River and maximum waterfall flow. The gorge spray keeps rock surfaces wet and slippery. Caution is essential.
July and August: Prime conditions. Rock surfaces are drier (though still wet near waterfalls), river flow moderates, and the longest days give you plenty of time for the full loop. This is the busiest period.
September and October: Excellent hiking conditions with cooler temperatures and thinner crowds. Fall color appears in the vine maple and alder along the upper sections. River flow is at its lowest, which actually reveals more of the rock formations in the gorge.
November through May: Forest Road 83 is typically gated closed from November through May or June due to snow. The trail is not accessible during this period.
What to Bring
- Sturdy hiking boots with aggressive tread: This is non-negotiable. The rock in the gorge is often wet and smooth. Trail runners and sneakers are a recipe for a fall.
- Trekking poles: Helpful for the descent into the gorge and the climb out. Stow them for the ladder section.
- Gloves: Useful for the ladder and cable sections, where metal can be cold and wet.
- Water (2+ liters per person): There's no reliable clean water source on the trail. The Muddy River lives up to its name.
- First aid kit: The rocky terrain and exposed sections create genuine injury risk. Carry the basics.
- Layers and rain shell: The gorge is cooler than the rim, and conditions change quickly on the flanks of Mount St. Helens.
Tips for a Better Hike
Hike clockwise. Descending the ladder is easier and safer than climbing it. The clockwise loop also puts the most dramatic gorge scenery in the first half of the hike, when you're fresh.
Start early. The trailhead parking lot is relatively small, and the 2-hour drive from Portland means most hikers arrive mid-morning. Leave Portland by 7 AM on summer weekends.
Don't skip the interpretive signs. The geological story here is genuinely fascinating. The 1980 eruption's mudflows traveled at 60 mph and deposited material up to 300 feet deep in some valleys. The canyon you're walking through was buried under thousands of years of soil and forest until those mudflows stripped it bare in hours.
Combine with Ape Cave. The trailhead for Ape Cave (the longest lava tube in the continental U.S.) is on Forest Road 83, about 10 miles before the Lava Canyon trailhead. You can do the lower section of Ape Cave in the morning (about 1.5 hours) and Lava Canyon in the afternoon for a full day of volcanic geology.
Check your gear before the descent. Once you're past the "End of Maintained Trail" sign and committed to the gorge, there's no easy shortcut back to the trailhead if you realize your boots don't have enough traction or you forgot water.
Nearby
- Ape Cave: A 2.5-mile lava tube, 10 miles west on Forest Road 83. Bring two light sources per person. 42 degrees F inside year-round.
- Climbers Bivouac: The starting point for Mount St. Helens summit climbs, about 15 miles north. Even if you're not summiting, the trailhead offers views of the south face.
- June Lake: A short, easy 2.8-mile round-trip hike to a scenic lake at the base of a lava flow, trailhead off Forest Road 83.
- Lower Falls Campground: The nearest developed campground with reservable sites, about 45 minutes south on Forest Road 90 near the Lewis River Falls trailhead. 43 sites, $22/night.
Lava Canyon shows you what a catastrophic volcanic eruption actually does to a landscape, not from a distant viewpoint, but by putting you inside the gorge itself. The suspension bridge, the ladder, the polished basalt, the recovering forest: it all adds up to one of the most memorable day hikes in Washington. Just make sure you're ready for it.
For the surface-level blast zone perspective on the same mountain, Norway Pass on the north side offers an entirely different angle on the 1980 eruption, with Spirit Lake views and standing silver snag fields from a well-maintained trail with no technical obstacles. Together, these two trails tell the complete story of what Mount St. Helens did to the surrounding landscape. For Portland and Seattle day-trippers, both are covered in the best hikes near Portland and best hikes near Seattle guides.