The NE margin of the Big Obsidian Flow, erupted from a vent near the south caldera wall of Newberry volcano about 1300 years ago, flowed into the crater of a pumice ring, whose forested rim is seen at the left and center. The pumice ring formed during an earlier Holocene eruption about 6400 years ago.

Photo by Lee Siebert, 1981 (Smithsonian Institution).

Newberry