El Dorado Lime & Mineral Company

California / Industrial / El Dorado Lime & Mineral Company

History

Limestone is one of the predominant minerals found throughout the rugged Sierra Nevada range. Extensive caverns and outcroppings of the calcium rich mineral formed out of the remains of marine life from the Paleozoic and Mesozoic eras, a time when entire the region was still sea bed. 1 This widespread availability of Limestone (used in the process of making mortar, steel, and glass) played a vital role in California’s industrial development. 2

El Dorado County was among the richest limestone producing regions in the state—where limestone had been mined and cooked since the 1870s. In the western foothills of El Dorado County, lies the Marble Valley, an area once home to several limestone mining operations. During the early part of the 20th century, the largest of the Marble Valley limestone producers was the El Dorado Lime & Mineral Company.

The company started life in mid-1916 as the El Dorado Lime Company, 3 with the intent to mine previously undiscovered limestone drifts in Marble Valley. Unlike the deposits located elsewhere in the state, the deposits in the Marble Valley are subterranean with no obvious outcroppings. In their first year of operation, the company established two kilns (40 short ton capacity) at a station along Central Pacific's Placerville branch called Limestone. 4

To move the limestone from the quarry to the new kilns in Limestone, the company built a 36” gauge railroad. Early mining efforts to supply the kiln focused on collecting the surface limestone. After burning in the kiln, the processed lime was sacked and shipped out in standard gauge cars. This operation was short lived. As the surface material exhausted, the company constructed a near vertical (80 degree) shaft alongside the large drifts below. This change in operation lead to the relocation of the kilns and railroad to Bullard station, 2.5 miles (4km) along the Central Pacific to the west. 5

The mine was built as a vertical stope through solid limestone to a depth of 360 feet (110m). Drifts 20 feet (6m) tall by 8.5 feet (2.6m) wide were worked on the 150 foot and 300 foot levels. Mining was carried out by tunneling into the drifts and blasting upward into the limestone faces in successive layers. The limestone fragments were then collected in 10-inch gauge ore cars from chutes spaced 30 feet (9.1m) apart along the drift edge.

Strings of ore cars were then moved above ground for processing. The limestone was then transferred into the grizzly, where it was broken by sledgehammer into pieces no larger than 18 inches in size. It then passed through a jaw crusher, followed by a hammer mill, before being screened into different grades. The final product was dumped into 36” gauge cars for transportation to Bullard for transloading into standard gauge cars. 6

The new 36” gauge railroad ran 1.9 miles (3km) from the mine to Bullard. Two Shay locomotives had previously been used at Limestone and continued service on the new line. Rolling stock consisted of 6-yard (4.5m3) capacity, 4-wheeled V-dump cars built by Koppel. Trains operating over the line were typically three cars long. Operation of the Shays was short lived, both were replaced in 1923 by a new Plymouth model DL-2.

The company reorganized as the El Dorado Lime & Mineral Company in 1922 with J. H. Bell as receiver. In September 1926 the State Mineralogist, it was reported that the company had twelve employees, seven of whom were miners, and was operating at a capacity of 100 tons per day. Limestone had become the primary mineral export of El Dorado County, and the operation at Bullard was the second largest in the county after the Mountain Quarries Company. 7

In October of 1931 the company once again reorganized, this time as the El Dorado Limestone Company. The railroad was converted to standard gauge around 1935 in conjunction with the arrival of a second hand Plymouth DLH-2; builder’s records indicate this locomotive was built as standard gauge. During World War II the mine shipped additional output by rail to the plant of Diamond Springs Lime Company where it was cooked in their kilns for shipment to steel mills. 8

After the war, increased freight car capacity, and weight, would lead the company to purchase a larger Plymouth locomotive secondhand from A. Teichert & Sons in 1952. Output from the mine continued to increase in the 1960s, and the main shaft was extended to the 1,200 foot (366m) depth with some additional stopes being developed at the 1,160 foot (354m) level in 1964.

In 1972, the E & J Gallo Winery purchased the company to supply limestone for their glass making needs. Underground mining ceased under the new ownership and the mine was allowed to fill with water. Limestone for processing instead came from another mine located to the north. In the early 1980s the Southern Pacific took over switching operations over the line until the company switched to trucking at the end of the decade.

The former right of way of this later line is now Amber Fields Road and serves as the main road into a gated community, making access difficult. The passing siding at Bullard remains in place though the El Dorado Western, who currently owns the line, recently relocated the switch. The mine site is still owned by Gallo. Operations of the plant finally ceased in the 1990s. The land is now part of a proposed housing development called Lime Rock Valley.

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1. Mary Hill. “Geology Of The Sierra Nevada”. University of California Press Berkeley, California.
2. Oliver E Bowen, "Limestone and dolomite resources of California." (California Divison of Mines and Geology Bulletin 194, Sacramento, 1973)
3. Mariposa Gazette, Volume LXI, Number 51, 27 May 1916.
4. G. F. Loughlin, "Mineral Resources of the United States 1918, Part 2 - Non Metals" (Department of the Interior Washington Printing Office, Washington D.C., 1918)
5. Mountain Democrat, July 27, 1918. Placerville, California.
6. "Mining Limestone at Shingle Springs, California", Engineering and Mining Journal-Press June 20, 1925
7. "Report 22 State Mineralogist Report" (California State Mining Bureau San Francisco Vol 22 No 4. October 1926 ), pg 440 - 441.
8. Clarence A. Logan, California Journal of Mines and Geology, Vol. 43, No. 3, July 1947, California Division of Mines, San Francisco, California, pp. 175-357.

Bibliography
Stone Quarries and Beyond - Cothrin Station through Garden Valley
Noble, Doug. "Mines of El Dorado County" El Dorado County Historical Society, 2002.
"Mining Limestone at Shingle Springs, California", Engineering and Mining Journal-Press June 20, 1925.

Reference Material Available Online

Reports

Report XVII of the State Mineralogist - Mining In California During 1921. California State Mining Bureau. Google Books Icon

Equipment Rosters

Locomotives of the El Dorado Lime & Mineral Co.

Maps

The Route of the El Dorado Lime and Mineral Co in Google Earth by Andrew Brandon.

Dugan and Bullard From 1916 ICC Valuation Map. National Archives (II) College Park, Maryland.

Limestone From 1916 ICC Valuation Map. National Archives (II) College Park, Maryland.

Photographs

Collected El Dorado Lime & Mineral Co. Photographs. Images collected from private collections, libraries and historical societies.

Links

Foothill Rails: El Dorado Lime & Mineral Co. - John Barnhill's page on the El Dorado Lime & Mineral Co.

Alex's Train Blog - El Dorado Lime & Mineral Co.

Limestone Production, El Dorado County. California Mineral Production for 1918 Latrobe through Shingle Springs (Continued). at Stone Quarries and Beyond by Peggy and George Perazzo

California / Industrial / El Dorado Lime & Mineral Company