MOUNT ST. HELENS, Wash. (AP) — Volunteers will be needed to repair the trailhead and reconstruct trail bridges on the Hummocks and Birth of a Lake trails near the end of the main west-side highway to Mount St. Helens.

Volunteers should gather Saturday at 9 a.m. at the Hummocks Trail parking lot, 43 miles west of Castle Rock on state Highway 504.

The next day, the anniversary of the catastrophic eruption of May 18, 1980 — U.S. Geological Survey scientist Joe Walder will give a presentation at the Johnston Ridge Observatory.

State road crews are trying to clear an unusually thick covering of snow from the highway and reopen the last nine miles to the observatory later this week.