Global Volcanism Program | Image GVP-06596
This pit crater on the SE rim of Medicine Lake caldera was formed during the first Holocene eruption of the volcano, about 4350 years ago. The eruption, which followed a quiescent period of about 6000 years, produced andesitic scoria from a NE-trending alignment of pit craters. Agglutinated spatter formed small lava flows.
Photo by Lee Siebert, 1998 (Smithsonian Institution).