Deep underground near the Salton Sea, in southern California’s Imperial Valley, lies one of the largest lithium deposits in the world. It has drawn the attention of clean tech entrepreneurs, climate activists, and politicians. A number of companies have already introduced plans to extract lithium from Salton Sea brine, and more are on the way. People are calling it Lithium Valley. A steady, reliable, ethically sourced supply of lithium is an essential part of a just transition to cleaner energy.