VANCOUVER, Washington (AP) -- Falling rocks at Mount St. Helens kicked up a dust plume Tuesday that rose above the rim of the volcano's crater, prompting second looks from the region's wary populace."We're having the first couple of rockfalls that we've had in a while ... and people can see it -- especially from Portland," said U.S. Geological Survey geologist Seth Moran at the agency's Cascade Volcano Observatory, about 50 miles south of the mountain.Overcast weather had hidden the mountain for weeks, and people tend to notice activity more whenever the peak comes back into view, Moran said.Mount St. Helens rumbled back to life in 2004 after years of quiet, with a flow of molten rock reaching the surface. In 1980, an eruption killed 57 people.Copyright 2005 The Associated Press. All rights reserved.This material may not be published, broadcast, rewritten, or redistributed.