These caves are formed almost entirely from steam fumaroles that send heat upward to bore out huge, cavernous rooms in steep passages. The eruption in 1980 created a vast crater with a north-facing breach - a virtual glacier factory. The smaller 2004 eruption reshaped the glacier and spawned a new generation of glacier caves.
This is an extremely young, active and dynamic sub-glacial environment, perfect for advanced studies in climatology, geothermal activity and microbiology.
For more on this project, watch this Oregon Field Guide show:
Discovery on Mt St Helens
Craig McClure, logistics expert and owner of Crackerjack First Response Specialists, helps guide the phone line into Godzilla Hole on Mt St Helens. The team uses military 'cricket' phones (their ring sounds like a cricket) for surface to in-cave communications. Radios don't work in caves.