Fig. 1Glass Mountain from the Medicine Lake caldera rim
Landform
A shield caldera east of Shasta — a high lake in a forested bowl, Glass Mountain’s obsidian on the rim, and a quieter fire country than Lassen’s road.
Field note
Glass Mountain is a black glass ridge on the rim. The lake sits in timber. This plate is Medicine Lake Volcano and Glass Mountain in Modoc National Forest, not Lassen Peak and not Crater Lake.
Medicine Lake is a shield caldera in Modoc National Forest — a high lake in timber, Glass Mountain’s obsidian on the rim. This plate is the Medicine Lake volcanic field, not Lassen Peak and not Crater Lake.
