OPB's Oregon Field Guide TV crews are preparing a program on glacier caves at Mount St. Helens.

OPB’s Oregon Field Guide TV crews are preparing a program on glacier caves at Mount St. Helens.

Ed Jahn/OPB

Recently, Snow Dragon — a glacier cave on Mt. Hood — suffered from a major collapse. Brent McGregor, the co-coordinator of the Sandy Glacier Cave Project, will join us to discuss what the collapse means for his caving expeditions and research on Mt. Hood.