October 17, 2005: my brother Joseph was visiting from Minnesota, so I took him hiking near Mt. St. Helens. Unfortunately, due to low clouds there was nothing to see from the Lahar Viewpoint near the trailhead, but the views in the canyon were undiminished. Most people who visit Lava Canyon either do the very short paved interpretive trail near the parking lot or the 1.3-mile loop to the suspension bridge and back. We went further down, all the way to near the junction with Smith Creek (at the end of Forest Road 8322), for a total of about 6 miles round-trip with 1330 feet of elevation change (2930' down to 1600').
It's a fascinating place: apparently the valley was filled by basaltic lava flows around 2000 years ago, and a gorge was subsequently eroded into the jointed lava by an ancestral Muddy River; but it was filled in over the centuries by material washing down the slopes of Mt. St. Helens. Then, in the eruption of May 18, 1980, the valley was assaulted by a lahar of epic proportions, scraping the basalt bare, washing out a bridge, and leaving a thick mudflow deposit in the lower valley. The exposed lava flows are full of interesting shapes, the countless waterfalls and rapids are beautiful, and the mud flats at the bottom -- from which you finally get a view of the volcano -- are a natural experiment in forest regeneration. The rocks and cliffs near the upper bridges are a lot of fun to climb around on, but apparently several people have died there, so be careful...
NOTE: Pictures whose filenames begin with "PJ" instead of "PA" were actually taken by Joseph with his camera.