Salton Buttes

Chain of five Holocene rhyolite lava domes on the southeast shore of the Salton Sea—Mullet Island, North and South Red Hill, Rock Hill, and Obsidian Butte—among California’s youngest volcanoes (roughly 1,800–3,000 years). The field hosts fumaroles, mud pots, and the Salton Sea Geothermal Field; Obsidian Butte was a major regional toolstone source. The pin favors the Red Island / Red Hill visitor-accessible cluster; hot ground and H₂S hazards are real.