The birth and death of county's salt industry

Solar evaporation to obtain salt can only be done in a few places on earth. First, there must be a source of salt water. There must be a climate with long periods of sun and very little rain. There must be wind movement to aid evaporation, and flat impervious soil. Lastly, there must be access to a market. These conditions occur in only three places in the United States: the Great Salt Lake in Utah, San Diego and the San Francisco Bay Area.

Some ponds fill with water only at extremely high tides and then have time to evaporate before the next very high tide. The salt can be scraped up off the hard packed ground. There were salt deposits just north of the present San Mateo Bridge and at Redwood City.

Around 1854, people in the Bay Area began creating man-made evaporation ponds. The first of these commercial operations was on the east side of the Bay near Hayward. The salt was full of impurities that made it unsuitable for table salt, but it had industrial uses. Refined table salt was imported from Europe.

The boom of the silver mines in the Nevada Comstock Lode in the 1860s created a massive demand for salt. Crude salt is used in the reduction of silver ore. The price of salt climbed to $162 per ton. With these profits, companies could buy equipment to improve the quality of the salt. By 1897, California provided most of the salt around the Pacific rim. The fishing industries of Alaska and Siberia used salt. Factories in Asia and Latin America making chlorine, ammonia, soap, bleaches, solvents and many other chemicals using industrial salt.

The East Bay companies began eyeing the west Bay for expansion. Before they could move in, however, several new salt companies opened on the shores of San Mateo County. C. E. Whitney Company started in 1903, but Whitney died that same year. The name of the company was changed to Leslie Salt Refining Company. Leslie was the first name of a member of the Whitney family.

Capital was needed to finance the expensive refining equipment, so there was a move to consolidate the small companies. In 1910, a modern refinery using a new vacuum-refining method was built in San Mateo that could produce fine table salt. To promote this product, a massive packaging and advertising campaign began. This marked the birth of the red cylinder container. It was claimed to be a stronger box than the other brands. By 1924, the local companies all had merged into Leslie California Salt Company. Success and consolidation caused the San Mateo plant to close in 1931 so that operations could be centrally located once again in the East Bay. By 1936, all of the Bay Area salt industries had consolidated. Now part of the Cargill Salt Company, the Leslie brand lives on because of the name recognition created by that 1910 advertising campaign.

Rediscovering the Peninsula appears in the Monday edition of the Daily Journal. For more information on this or related topics, visit the San Mateo County History Museum, 777 Hamilton St., Redwood City.