While Mount St. Helens is grabbing the headlines for every little burp it makes, Rainier is constantly letting out gas of its own, according to USGS Hydrologist and Outreach Coordinator Carolyn Driedger.

"You have steam rising from the summits of both volcanoes," Driedger said in a phone call Monday afternoon. "It's just a more visible steam plume than normal."

It certainly stood out to me while driving north on I-5 across the Nisqually delta on a very clear Sunday afternoon. The puffy cloud could even be seen from the KING 5 Tower Cam on Queen Anne in Seattle. You'll have to trust me on that - the screen shot I've got here doesn't do justice to what it looked like.

Driedger assured me there was nothing big going on at the tallest volcano in the Cascade Range. "It's steaming full-time on Rainier and enough to keep it snow-free year-round around the vent."

Driedger said her office also gets calls this time of year from folks who ask if the puffs of dust sometimes seen coming from high up on the mountain are ash coming from some new vent. It's a more mundane explanation they usually get - dust kicked off exposed ridges where the snow has melted away.

This is also the time of year you're more likely to see small debris flows - a churning mix of water, mud and rock - rushing down the flanks of the mountain, said Driedger, who's studying them when she's not talking to curious media types with some time and a telephone.