The Sailor Flat and Irish Creek mine was a 160 acre placer gold mine one and one-half miles south of Garden Valley.
Two miles north of Georgetown, in the Georgia Slide area, was a 29.66 acre placer gold mine known as the Sailor Slide mine. It was active from 1919 to 1922.
One mile northwest of Kelsey on 20 acres of the Mother Lode was a lode gold mine known as the St. Clair mine. It was active prior to 1915 and again around 1940.
The St. John mine was a 183.03 acre placer gold mine located seven miles east of Georgetown and five miles southeast of Volcanoville, near Chiquita.
The St. Lawrence Group operated a lode gold mine on 25.52 acres of the Mother Lode, one and one-half miles southeast of Garden Valley. From 1867 to 1878 nearly a half-million dollars in gold (at 1870s prices) was produced from a six foot wide vein of gold-bearing quartz that ranged from $8.54 to $27 per ton in gold, but averaged from $10 to $17 per ton. By the time the 500-foot level had been reached, $2,000,000 in gold had been removed. The deposit was developed by a 900-foot inclined shaft with a working level at 100 feet and a 200 foot winze at the 900-foot level. The ore was treated in a twenty-stamp mill.
Another St. Lawrence mine was a seam gold mine that yielded $23,000 in gold by hydraulicking. Because the gold was hydraulicked, this is probably the St. Lawrence and Florida placer gold mine which consisted of 98.56 acres and was one mile south of Greenwood.
The St. Lawrence No. 2 mile was a lode gold mile on 5.45 acres of the Mother Lode two miles northeast of Kelsey. This could be a part of the St. Lawrence Group’s workings.
The St. Louis mine was lode gold mine on the Mother Lode three and one-half miles south of the townsite of El Dorado.
A second St. Louis mine was a lode gold mine consisting of 18.77 acres on the Mother Lode, one and one-half miles southeast of Garden Valley.
Three miles southeast of Diamond Springs was the Salisbury mine, a lode gold mine on the Mother Lode. It is adjacent to and an extension of the very rich, Grand Victory mine. A vein of gold-bearing quartz, 100 feet in width, was actively mined from 1896 on and developed by a 110-foot inclined shaft. The ore, which varied in value from $8 to $30 per ton depending on the depth from which it was taken, was treated in two twenty-ton Huntington mills.
One mile north of Greenwood on 20.66 acres of the western branch of the Mother Lode was a seam gold mine known as the Sam Martin (San Martin?)mine. It was active in 1894-96 and consisted of a 20-foot wide zone of quartz seams in slate. The upper portion of the deposit was mined by sluicing and the lower portion mined through an 80-foot adit. The mine was equipped with a 200-foot flume.
The Samuel Fleming mine was an 80 acre placer gold claim one mile north of Pleasant Valley near Newtown.
The Samuel H. Maginess mine was a 400 acre placer gold claim two miles southeast of Camino on the north side of the South Fork of Weber Creek.
The Sand Mountain mine was a placer gold mine at an unknown location, but probably near Sand Mountain, 11 miles east of Georgetown. It did have a ten-stamp mill.
The San Francisco Slate Company operated slate mines on the north side of the South Fork of the American River, opposite Chili Bar. During the 1890s roofing slate was produced from several quarries at this location.
The Santa Claus mine was a lode gold mine consisting of 20 acres on the western branch of the Mother Lode, one-half mile north of Greenwood.
The Santa Rosa mine was a placer gold, drift mine on Hopkins Creek, one mile east of Volcanoville. During the years 1894 through 1896, a southwest trending channel of gold-bearing gravel was developed by a 718-foot adit.
The Santa Ynez mine was a lode gold mine on the Mother Lode two and one-half miles south of the townsite of El Dorado. The workings consisted of four mines, the Santa Ynez, Sam Hill, Lookout and Mohawk, consisting of a total of 61.631 acres.
The Sardine mine was a placer gold mine four miles northwest of Greenwood near the Middle Fork of the American River.
The Scaroni (Melton) mine was a lode gold mine located two miles north of Grizzly Flat
The Scheel mine was a placer gold mine on 20 acres, six miles southeast of Indian Diggings, just north of the South Fork of the Cosumnes River.
The Schleifer mine was a lode gold mine on the west side of Big Canyon, seven miles south of Shingle Springs. The deposit was low grade auriferous pyrite and was actively mined prior to 1894.
The Schneider and Co. mine was a lode gold mine one mile south of Diamond Springs on the Mother Lode.
The School Girl mine was a lode gold mine on 32 acres of the Mother Lode two miles southeast of the townsite of El Dorado. It would become part of the Union mine.
The Schwalin Marble Quarry was located on 13.47 acres three miles southeast of Clarksville on Marble Creek.
The Sebastopol mine was an 18.87 acre lode gold mine three miles north of Greenwood at Spanish Dry Diggings.
One mile east of Diamond Springs on 60 acres of the Mother Lode was a lode gold mine called the Selby mine. It was active prior to 1900 and developed by a single 240-foot shaft. It is reported to have processed pyrites for the nearby Larkin mine.
In 1939 the Sells Brothers, who were from Auburn, operated a dry-line dredge in the very northern part of El Dorado County, south of the city of Auburn.
The Serpentine mine was a lode gold mine located two and one-half miles northwest of Georgetown on the eastern branch of the Mother Lode.
The Seven Bells (Sporting Boy) mine was a copper mine four miles west of Placerville. A vein of copper and gold up to eighteen inches wide, it was prospected in 1917 and 1918 and developed by a 65-foot shaft.
The Shady Side (Shadyside) mine was a lode gold mine located one and one-half miles south of Greenwood on the western branch of the Mother Lode. It was later operated together with the Sunrise mine, the two consisting of a total of 30.722 acres.
The Sharp mine was a lode gold mine located six miles east of Placerville. It was first opened about 1870 and was again active twenty years later. The 12-foot wide vein of gold-bearing quartz was developed by a 54-foot shaft along with 110 and 108-foot adits.
The Shaw (Shan Taz, Shan Tsz, Volo) mine was a lode gold mine located two miles north of the townsite of El Dorado and four miles southwest of Placerville. It was one of the better-known lode gold mines on what is often referred to as the West (gold) Belt in El Dorado County. The mine was originally active during the 1880s and again around 1915. In 1940 the Volo mining company leased the property and during 1941 and 1942 some ore was mined and milled experimentally. In 1942 the mine was shut down and then reopened in 1946 and operated until 1953. During the years 1943 and 1944, when the mine was inactive, and after it was shut down, the mill was used to process copper ore from as far away as the Copper Hill mine in Amador County. The ore body, which is a quartzitic schist, averages about 100 feet in width and has been worked for about 1000 feet. Prior to 1915, the mining was done underground through a 135-foot shaft, a 400-foot crosscut adit, a 300-foot south drift and a 200-foot north drift. When the mine was reopened in 1940, the mining method was shifted to an open cut that by 1955 was about 1000 feet long, 100 to 150 feet wide and 20 to 40 feet deep. The ore, which was relatively low grade containing only $2 to $4 of gold per ton, was blasted from the pit faces and trucked to the mill where it was treated by amalgamation (mercury) flotation and cyanidization.
The Shelly (Wolf) mine was a chromite mine located two miles southwest of Garden Valley. It was active in 1918, when chromium was a critical metal for the war effort, when 1,284 tons of ore containing 30 percent chromite was mined. The deposit, which consisted of irregular lenses of chromite in serpentine, was developed by an open pit and a shaft.
The Shepard mine was a lode gold mine on 12.43 acres of the western branch of the Mother Lode, one mile northwest of Greenwood.
The Shepard and Co. mine was a lode gold mine on 7.34 acres adjacent to the south boundary of Placerville.
The Sheplar and Co. mine was an 80 acre placer gold mine one-half mile east of Smith Flat.
Two miles west of Garden Valley was the Sheppard mine, a chromite mine. It was active during World War I, when more than 50 tons of 35 percent chromite ore was produced. This deposit also consisted of lenses of chromite in serpentine and was developed by open pits and shafts.
On the Mother Lode one mile north of Placerville was the Sherman mine, a lode gold mine. It was active in 1905 and 1908-11 with a total production of $136,000. The deposit, a five foot wide vein of gold-bearing quartz, was developed by a 750-foot inclined shaft with levels at 100, 200, 300, 400, 500, and 750 feet; a winze sunk from 750 feet and 5500 feet of drifts. The ore was treated in a mill that had ten 1000 pound stamps.
A second Sherman mine was a placer gold mine consisting of 80 acres one-half mile east of Smith Flat.
One mile east of Shingle Springs was a soapstone mine known as the Shingle Springs (Rossi) mine. Lenses of green soapstone in serpentine was developed by an open pit. The mined material was shipped for use as a roofing coating.
Another Shingle Springs mine was a quicksilver (mercury) mine five miles south of Shingle Springs. Only traces of cinnabar, an ore of mercury, was found at this location.
The Shoemaker mine was an 80 acre placer gold mine two miles southeast of Georgetown.
The Shumway mine was a lode gold mine on the Mother Lode one mile southeast of Spanish Flat. It was prospected in 1938 and developed by a 100-foot shaft and 300-foot crosscut adit.
The Sierra Placerite quarry is one of the few dimension stone mines in El Dorado County. It is located just north of the junction of Newtown and Pleasant Valley roads in Pleasant Valley. The deposit, large beds of vitric crystal rhyolite tuff of Miocene age, some several hundred feet thick, occur in the region. The fine grained material is mined from open pits and then sawed and broken into the desired size for walls, building fronts, fireplaces, decorative items and the like. Naturally a light buff to white in color, it is often “cooked” to drive off moisture, which changes the color to shades of orange, red or pink. The “Rhyolite Building” on the north side of Pleasant Valley Road in Diamond Springs was constructed with material from this quarry.
The S. H. Goen and S. W. Wybles mine was a placer gold mine one and one-half miles north of the townsite of El Dorado.
The Sylvester (Silvester) and Schleicher mine was a placer gold mine of approximately 30 acres in size three miles south of Coloma in the Gold Hill area.
This mine surrounded another Silvester and Schleicher mine which was a 19.66 acre lode gold mine.
Two miles southwest of Garden Valley was a chromite mine known as the Simon mine. Like many of the others it was active during and right after World War I, when 94 tons of 35 percent chromite ore was produced. A deposit of lenses of chromite in serpentine, it was developed by open cuts.
The Simons mine was an iron prospect one and one-half miles south of Latrobe, near the Chaix mine. The deposit contained two ores of iron, magnetite and hematite.
The Simpson mine was a chromite mine located five miles north of Clarksville (Clarksville is near the southern end of El Dorado Hills). It was active in 1917, when 54 tons of ore of unreported purity was produced. The deposit of lenses of chromite near a serpentine-schist contact was developed by open cuts and shallow shafts.
The Sir Raleigh mine was a lode gold on the Mother Lode, one and one-half miles northeast of Diamond Springs.
The Skipper (Esperanza) mine was a lode gold mine located one-half mile east of Greenwood on the western branch of the Mother Lode. An unpatented claim known once as the Esperanza, the deposit consisted of a zone of gold mineralization 60 feet long and 40 feet wide. It was developed by an open cut with a 50-foot inclined shaft sunk in the bottom of the cut. There are also several other cuts and prospects on the property.