The salt operations at the southern end of the San Francisco Bay are the largest, in area, in the country. Cargill (a privately held industrial conglomerate with around 143,000 employees worldwide) owns all the salt operations on the bay, having bought the bay area's main salt producer, Leslie Salt, in 1978. Salt brine is shifted from pond to pond over a five year period through a system of 8,000 acres of ponds until it is saline enough that it grows as a crystal from the bottom of the crystallizing ponds (the ponds are often a deep red color because of an algae that grows naturally). It is then scooped up from the bottom of these ponds and is washed, ground, and packaged. Though Cargill owns the ponds and does the harvesting, some of the raw salt is sold and packaged by Morton Salt, which has a refinery adjacent to Cargill's. Morton and Cargill are also neighbors at the Great Salt Lake in Utah, another major salt production site. Outside the Southwest (where salt water can be evaporated) salt is generally obtained from salt mines, in Kansas, Louisiana, New York, and elsewhere.
Cargill Salt, California