The Red Hill Cinder Mine is an active volcanic site in the Coso Volcanic Field where red and black cinders are extracted from a cinder cone. What makes this spot so unique, however, is volcanic bombs that have been thrown out during previous eruptions-large pieces of solidified lava. These bombs have been picked up and placed around the mining company’s office buildings.
Red Hill is one of the youngest volcanic formations in the area, with an estimated age of less than 10,000 years. A small flank eruption on the cone could have occurred within the last 1,000 years. If you drive south down Highway 395, you can see the small crater from that eruption on the northwest side of the cone.
CEMEX currently mines the Red Hill Quarry on the south flank of the cinder cone, crushing the volcanic rock into scoria for use in road construction and the manufacture of cinder blocks. Larger pieces of the rock are also used for landscaping.