The Mono–Inyo Craters are a chain of volcanic craters, domes, and explosion pits located in eastern California, USA, extending from the northern shore of Mono Lake to the south of Mammoth Mountain. This north-south trending volcanic chain is part of the active Long Valley volcanic region and is associated with a series of eruptions that occurred over the past 40,000 years, with the most recent eruptions dating to approximately 600 years ago.
The volcanic features include cinder cones, lava domes, and phreatic explosion craters, formed by both explosive and effusive eruptions. Notable features within the chain are Panum Crater, a well-preserved rhyolitic tuff ring and lava dome, and Inyo Craters, a group of explosion pits formed during steam-driven eruptions.
Geologically, the Mono–Inyo Craters are linked to a fissure system that reflects basaltic and silicic magmatism associated with crustal extension in the western margin of the Basin and Range Province. The eruptions are believed to be driven by the intrusion of magma along narrow dikes, with periodic eruptions of both basalt and rhyolite.
The area is monitored by the United States Geological Survey (USGS) as part of the Long Valley Caldera monitoring program due to ongoing seismic activity and ground deformation, indicating that the volcanic system remains potentially active.
The Mono–Inyo Craters lie within the Inyo National Forest and are accessible to the public, serving as a site of scientific research and geological tourism.