While trying to find a plowed road through the highlands northeast of Mount Shasta in northern California, I asked a local what he knew about this Biden monument, but he hadn’t heard of the park we were both in. He referred to the area as the Medicine Lake ridge, and he suggested that nearby Glass Mountain was also worth visiting. Medicine Lake above is named for the large low profile or ‘shield’ volcano it sits below. The high point is almost 8,000 feet, but the whole area is high enough to have snow drifts blocking roads in May.

Sáttítla means ‘Obsidian’ in the local native language, and Glass Mountain is loaded with the black volcanic glass. To be clear, this is the Glass Mountain in Modoc National Forest near Lava Beds, not the 11,000+ foot Glass Mountain in the Inyo National Forest near Yosemite. The road and hiking are rough in this US Forest Service monument, and it’s illegal to gather obsidian. Fortunately the active volcano hasn’t erupted in 1000 years or so. But geologically, this is still a fascinating area.

The many volcanoes in Northern California, like Lassen and Shasta, are created by action deep below the surface. Until I got lost up here, I never knew that when one of the tectonic subduction plates slides under the continent, it can slice off a top surface layer, leaving contrasting features. Besides sharp peaks like Black Butte aside 101, there are faults that cause water falls like Middle Falls near McCloud below on its way to Shasta Lake.