The Red Cones last erupted approximately 5000 years ago,[2] with both cinder eruption (forming the cones), and a basalt flow from the southern cone, which flowed approximately 1.5 kilometers (0.9mi) towards the upper Middle Fork of the San Joaquin River.[3]
The Red Cones are at the southern end of the Mono-Inyo Craters, the magma for the Red Cones shares its origin with the other Mono-Inyo craters.