Northern California’s Sáttítla Highlands are a testament to the region’s volcanic past, with the landscape dramatically shaped by millions of years of eruptions.
The area, dominated by the expansive Medicine Lake Volcano, has a rich history of both geologic activity and cultural significance, being part of the ancestral homelands of the Pit River and Modoc Peoples.
Fiery History of the Sáttítla Highlands
The Sáttítla Highlands in Northern California are a testament to a fiery past, with volcanic activity shaping the landscape for over a million years. Today, remnants of ancient lava flows and eruptions are still visible across the region.
The Sleeping Giant: Medicine Lake Volcano
At the heart of Sáttítla lies the Medicine Lake Volcano, a massive shield volcano and one of the two largest in the Cascades Volcanic Arc. Over thousands of years, intermittent eruptions—mostly gentle, lava-producing events known as effusive eruptions—have gradually built its expansive structure. The volcano’s central caldera now holds Medicine Lake, a striking volcanic feature captured in the image abive taken by the Operational Land Imager (OLI) on Landsat 8 on October 7, 2024.
The volcano has erupted nine times in the last 5,000 years, and some of those began with explosive phases. For example, two of the most recent eruptions sent ash tens of miles downwind before a slow effusion of thick lava (obsidian) formed Little Glass Mountain and Glass Mountain about 1,000 years ago. Glass Mountain’s steep-sided rhyolite and obsidian flow spans 14 square kilometers.
Cultural and Environmental Significance
The Indigenous Ajumawi name “Sáttítla” translates to “obsidian place,” and the highlands contain portions of the ancestral homelands of Indigenous communities. On January 7, 2025, over 224,000 acres of these highlands were designated as a U.S. national monument, including portions of the homelands of the Pit River (Ajumawi – Atsugewi) and Modoc Peoples (Mo Wat Knii – Mo Docknii).
The image shows bare lava fields interspersed with islands of vegetation and surrounded by green forests. Sáttítla Highlands National Monument encompasses parts of the Modoc, Shasta-Trinity, and Klamath national forests. The region is home to rare and vulnerable flora and fauna, including the Cascades frog, the northern spotted owl, the long-toed salamander, and the sugarstick—a parasitic plant associated with the roots of old-growth conifers.
Over 80 plant species found here are used by Indigenous communities for medicine, food, tools, and ceremonial purposes. Obsidian tools have been found within the area, which were crafted by Indigenous communities throughout the region.
NASA Earth Observatory image by Wanmei Liang, using Landsat data from the U.S. Geological Survey.
Never miss a breakthrough: Join the SciTechDaily newsletter.
Follow us on Google and Google News.