In the late 1800s and the first part of the 20th century, leather tanneries were part of daily commerce. Two local tanneries were the Beeger Tannery and Frank's Tannery.

One of the essential components of preparing leather hides was to cure them with salt. As such, demand for commercial salt production was on the rise.
At the turn of the 20th century, three companies acquired land and launched salt production operations. They were West Shore Company, Redwood City Salt Works and Greco Salt Company. However, another company would eventually emerge and dominate the local salt production industry.
Enter C.E. Whitney Company.
They began operations in 1892. In 1904 the founder died. At that point, the name was changed to Leslie, after a family member, and became known as Leslie Salt Refining Company.

Not long after this, the Stauffer Chemical Company purchased West Shore and Redwood City Salt Works. Then in 1907, the two entrepreneurs decided to consolidate their businesses, resulting in the emergence of the Leslie Salt Company.
By 1924, only a handful of salt production companies remained. Another consolidation took place that year. California Salt Company and Continental Salt & Chemical merged with Leslie to form Leslie-California Salt Company. Then in 1931, Oliver Salt Company was absorbed by Leslie.
In the end, Leslie became the dominant player. Only one other salt production company remained- Arden Salt Company. However, in 1936 they merged with Leslie.
The Leslie Salt Company acquired 2,000 acres of Bay land in just a few short years. The company's land ultimately grew to 3,500 acres by 1940.
At the Redwood City port, they constructed a loading dock and two towers which were used for loading more than one ship at a time.

At its peak, Leslie's annual production was 500,000 tons of bulk salt. The Port of Redwood City became dwarfed by the enormous white mountain of salt. The 'salt mountain' was so visible it was used by incoming aircraft as a navigation point.
Over the years, advanced technology, including synthetic leather, brought the demise of tanneries. Beeger Tannery shut down in 1947, and the land became an automobile dealership. Frank's Tannery shut down in 1959. It burned to the ground in a spectacular fire in 1968.
In 1978, Leslie sold the company to Cargill Salt. The Leslie name was kept until 1991. In 2006, Cargill closed the Redwood City location.
After more than 100 years, salt production was no more, and the vast 'salt mountain' was swept into our memories.
Everything else is just history
Some of the photos used in this blog are courtesy of the Local History Room, Redwood City's best-kept secret. The Local History Collection covers all aspects of Redwood City's development, from the 1850s to the present day, with particular emphasis on businesses, public schools, civic organizations, city agencies, and early family histories. The Local History Room is not affiliated with the Redwood City Public Library, but it is inside it.