The 1920s were a difficult decade for the residents of Calaveras County. While much of the country thrived during the years that came to be called the “Roaring Twenties,” the population of Calaveras County declined to its lowest level since the beginning of the Gold Rush.
During World War I, most of the gold mines closed down due a combination of rising production costs and a fixed gold price. While those involved directly in mining operations lost their jobs, all of the subsidiary industries that catered to the mining industry were also hit hard.
In 1924, a 45% majority of the county’s residents cast their ballots for the presidential candidate of the Socialist Party, Robert M. LaFollette, Sr. And this in a conservative county where the majority of residents, including the miners themselves, had long opposed the unionization of even the highly dangerous deep-shaft mines.
In a period of economic decline, there was one encouraging development: the opening of the Calaveras Cement Co. plant outside of San Andreas in 1926.
At the turn of the 20th century, California was growing at a rapid rate. Burgeoning urban centers increased demand for cement, and the nascent industry struggled to keep up.
In the early 1920s, William Macnider, an industrial salesman active in Northern California, optioned several limestone deposits in Calaveras County with the idea of developing a cement industry in the area.
William Wallace Mein and George B. Poore, two mining engineers based in San Francisco, became aware of Macnider’s activities and decided to buy him out.
The pair had recently returned to California from Witwatersrand, South Africa, where they had been active in various gold mining operations.
In 1924, the two men formed a syndicate and began building a cement plant at Kentucky House, an old stage stop along Calaveritas Creek to the south of San Andreas.
In order to get their product to market, they first worked with the Southern Pacific Railroad to extend its Lodi branch from Valley Springs to Kentucky House.
Southern Pacific agreed to lay eight miles of track from Valley Springs to just south of San Andreas, while the Calaveras Cement Co. took responsibility for constructing the line the rest of the way.
On Dec. 24, 1925, the railroad was completed. This allowed the company to bring in heavy machinery, and the construction of the plant proceeded at a rapid pace thereafter.
On May 9, 1926, the company held an open house and barbecue that drew an estimated crowd of 15,000 people – more than one and-a-half times the county’s population. It was the largest gathering in Calaveras County up to that point.
The first batch of cement was shipped by rail on June 14, 1926.
The first large order, for the construction of the Pardee Dam, was placed later that year.
While many businesses closed their doors during the Great Depression, the Kentucky House plant thrived, managing to double its production during the 1930s.
During World War II, demand for cement again increased, and the plant underwent a series of expansions in the 1940s and 1950s.
By the end of the 1950s, five kilns produced 650,000 tons of cement annually.
In 1959, the original owners sold out to the Flintkote Co., a nationwide manufacturer of building materials. The company expanded its distribution network and built a new plant in Redding in 1961.
By 1971, the company’s limestone quarries around San Andreas and Calaveritas had played out, and a new source of raw materials was needed.
A new quarry was developed at Cataract Gulch on Camp Nine Road outside of Murphys. The limestone was transported to the Kentucky House plant through a 17-mile underground slurry line in which a mixture of limestone and water was conveyed through 8-inch pipe at 2,500 pounds of pressure.
In 1979, a Canadian company, Genstar, bought out the Flintkote Co.’s cement manufacturing operations in Calaveras County.
Unfortunately, by the early 1980s, increases in the costs of production along with the availability of cheaper cement from China combined to close down the Kentucky House plant in 1983.
By the time of its closure, the plant had been in continuous operation for 56 years. During 40 of those years, it had been the largest private sector employer in Calaveras County.
At its height, the Kentucky House plant employed 450 people. By the time it closed, that number was down to only 136.
Following the plant’s closure, the heavy machinery was sold off. Demolition of the site didn’t begin until 2005, and wasn’t completed until 2013.
In that year, a row of 100-foot-tall silos, which could be seen from Pool Station Road since the plant expansions of the 1950s, finally came crashing down.
During its five-and-a-half decades of operation, the Kentucky House plant provided cement for projects across the state of California.
Calaveras cement was used to build the California Aqueduct, the San Francisco-Oakland Bay Bridge, the McClellan and Travis Air Force bases, the San Francisco Airport and the Oroville Dam, among many other projects.
The construction of the Parrotts Ferry Bridge in the late 1970s was one of the last projects to use cement from the plant.
While Calaveras County is best known for its gold, no single gold mine ever contributed more to the county’s regional economy than the Kentucky House cement plant.
Although the end of cement production was a big blow for Calaveras residents, the county was able to quickly bounce back.
Between 1979 and 1990, Calaveras County’s population grew by three-fifths, finally matching and exceeding its peak of 20,183 at the height of the Gold Rush.