The Table Rock mine was a placer gold mine consisting of 11.27 acres on the north side of the South Fork of the American River, two miles north of Placerville on the south side of Rock Creek Road.
There were several mined and apparently unnamed talc deposits in the area of Latrobe. One was about three miles northeast of the town and the other about one and one-half miles northeast. There is no information on how much material was mined or for how long they were active.
The Tanksley mine was a placer gold mine consisting of 30 acres one and one-half miles east of Georgetown near Hotchkiss Hill.
The Taylor mine, also known as the Idlewild mine, was a large, lode gold mine on the 16.49 acres of the western branch of the Mother Lode two miles (one publication says four miles) northwest of Garden Valley on the western branch of the Mother Lode. Originally worked in 1865, it laid idle for a number of years and was active again from the late 1880s to about 1902 when some $50,000 of improvements were done including the installation of a 20-stamp mill, which was later increased to 40 stamps. During that time it was listed as the principal producer of gold in the county. Some additional work was done at the mine during the years 1939-41.
The vein of gold bearing quartz averaged 14 feet in width and produced $4 to $8 in gold per ton of ore. The mine was developed by a 1230-foot inclined shaft with levels every 100 feet. At the 600-foot level there was a winze to the 1230-foot level. The quartz vein started decreasing in size below the 500 foot level and by the ninth level there was no quartz nor gold. 100 foot crosscuts were dug at the tenth and eleventh levels without luck. Similar crosscuts were dug at the second and third levels to the edge of the property in search of other veins. None were found.
Mining was done by stoping with the voids being later filled with mine waste. Ore was crushed by a huge 40-stamp mill and the concentrates treated with cyanide. The estimated total output of the mine was one-million dollars.
The Teddy Bear Group operated one or more lode gold claims on the Mother Lode, three and one-half miles south of the town of El Dorado. One mine was called the Teddy Bear.
The Telegraph mine was a placer gold mine on 40 acres located two and one-half miles south of Omo Ranch. Adjacent to it was the Telegraph No. 2 mine, a 20 acre placer gold mine.
The Tennessee Creek mine was a 120 acre placer gold mine one-half mile north of Shingle Springs. From its name one can tell it was located on Tennessee Creek which flows north into Weber Creek.
The Texas Bar mine was a placer gold mine consisting of 26.99 acres on the south side of the Middle Fork of the American River, two and one-half miles northeast of Cool.
Two miles southeast of Placerville, at Texas Hill, was a placer gold mine known as the Texas Hill mine. It was active around 1894 when an ancient channel of the South Fork of the American River, with a deposit of gold-bearing gravel one to three feet thick and up to 100 feet wide, was developed by a 1500-foot drift, a 75-foot incline and a 157-foot shaft. The cemented gravel was treated in a ten-stamp mill and then washed in a 100-foot sluice. To get to the deposit the miners had to tunnel through 120 feet of andesite (lava).
The Theodore Rupley mine was an 80 acre placer gold claim on Empire Creek, eight miles east of Camino.
The Thistle mine was a placer gold mine consisting of 110 acres one and one-half miles north of Smith Flat.
The Thomas and Meldrum mine was a chromite mine located two miles east of the town of Rescue. It was active only during World War I when one carload of ore was produced from stringers and pods of chromite in a serpentine deposit. Development was by two shafts of unknown depth.
The Thomas Alderson mine was a 40 acre placer gold claim one and one-half miles east of Smith Flat.
A second Thomas Alderson mine was an 80 acre placer gold claim on the southern boundary of Placerville as it was in 1938.
The Thomas Cruson and Rufus B. Olmstead mine was a 40 acre placer gold claim one-half mile north of Smith Flat.
The Thomas Fraser mine was an 80 acre placer gold claim three miles east of Diamond Springs.
The Thomas Ward mine was a 147.78 acre placer gold claim one and one-half miles north of Smith Flat.
The Thorsen mine was a placer gold mine one mile northwest of Pleasant Valley.
One mile south of Rattlesnake Bridge, immediately east of the Zantgraf Mine, was the Threlkel (Winton) mine, a lode gold mine. It was active in 1924-26 and again in 1937, when a deposit consisting of several thin veins of high grade, gold-bearing quartz were mined through an adit. The ore was treated in a two-stamp mill. The mine is now a part of the Folsom Lake Recreational Area.
The Ticino and Swiss American mine was a lode gold mine on 61.15 acres eight miles east of Pleasant Valley.
One and one-half miles south of Kentucky Flat (south of Volcanoville and east of Georgetown) was a drift and hydraulic, placer gold mine known as the Tiedemann (Tiederman) mine. It was active prior to 1896 and from 1896 until 1902 when the Two Channel Mining Company operated it. It was again active from 1932-34. There were two channels of ancient river bed worked at this location. The main, or white, channel was hydraulicked while the blue channel was developed by two adits, one of which was 100 feet in length.
The Tin Cup mine was a lode gold mine on the Mother Lode two miles south of Placerville. It was operated together with the adjacent Ribbon Rock mine. By 1900 a ribbon of gold bearing quartz had been followed 200 feet into the earth, making it the best property in the area at that time.
The Tipton Hill mine was a placer gold mine at Tipton Hill, seven miles northeast of Georgetown and about one mile south of Chiquita. Here, many years ago, a channel of the ancient Middle Fork of the American River was mined by drifting and hydraulicking.
The Tiree mine was a placer gold mine consisting of 40 acres and located one and one-half miles southwest of Placerville.
The Titler and McAvin mine was a 40 acre placer gold claim two miles east of Smith Flat.
At Smith’s Flat, east of Placerville, was a placer gold, drift mine known both as the Toll House and Hook and Ladder mine. It was originally active prior to 1890 when two shafts were sunk “to a considerable depth.” After repairing the shafts and tunnels and installing new equipment in the 1890s, a significant amount of new work was done. The mine was later reopened and worked from 1918 until 1932. Through a network of shafts, raises and several thousand feet of drifts, the miners worked the Deep Blue Lead (lead as in “to lead you”, not the metal lead) and Gray Lead channels of the ancient South Fork of the American River.
The Tong Quartz mine was a lode gold mine one-half mile east of Clarksburg, south of today’s El Dorado Hills. Located on 10.33 acres it is probably very close to or possibly partially covered by today’s Highway 50.
The Treat mine was a lode gold mine located two and one-half miles north of Grizzly Flat. 10.31 acres in size, it is sometimes shown as the Treat Extension of the Eureka mine. It was active prior to 1888 and again in 1896 when a vein of gold-bearing quartz was developed by a 100-foot vertical shaft and adits of unreported length.
The Trench (Yellowjacket) mine was a lode gold mine in Quartz Canyon, one mile south of Volcanoville. It was active prior to 1894, but has been idle for a long time.
The Trimble mine was a placer gold mine consisting of 100 acres. It was adjacent to the Tanksley mine, one and one-half miles est of Georgetown, near Hotchkiss Hill.
The Trinity mine was a placer gold mine two miles northeast of Omo Ranch near the Steely Fork of Grizzly Creek. It consists of two separate claims totaling 270.27 acres in size.
During World War I the Trio Chrome Company placer mined chromite-bearing gravel from the Hoff and Helmar properties, five miles southeast of Latrobe, near the Cosumnes River.
The Tropper mine was a chromite mine one and one-half miles west of Garden Valley. It was active in 1918 when 110 tons of ore was mined. The deposit, a lens of chromite ten feet wide was developed by a 40-foot inclined shaft.
The Trowbridge mine was a lodge gold claim on the Mother Lode, two miles southeast of the town of El Dorado.
The True Consolidated mine was a group of mines about one mile north of Placerville on the Mother Lode. There are several references to this mine or mines, but not much information other than that they were operated in the late 1800s and early 1900s by the True Consolidated Mining and Milling Co.
The Try Again (Last Chance) mine was a placer gold, drift mine three miles east of Placerville. It was active around 1896 when an ancient channel of the South Fork of the American River was developed by a 1500-foot bedrock adit and 213-foot shaft.
The Tullis mine was a lode gold mine located on 15.65 acres of the Mother Lode, one mile southeast of the townsite of El Dorado and one mile south of Diamond Springs. It was active in 1896 when a two and one-half foot wide vein of gold-bearing quartz was developed by a 200-foot inclined shaft and 175 feet of drifts. It is the source of the name Tullis Mine Road, which is on the western side of Diamond Springs.
The Tunnel Point mine was a placer gold mine consisting of 50 acres on the South Fork of the American River one mile down-river from Coloma.
The Turnboo Group operated a lode gold claim that was located four miles south of Shingle Springs.
In 1949 the Twin Forks Dredging Company operated a dragline dredge on the North Fork of the Cosumnes River near Youngs (a short distance up river from where Mt. Aukum Road now crosses this fork of the Cosumnes).
The Two Channel Mining Company operated numerous drift and hydraulic mines in the Volcanoville-Kentucky Flat area until about 1908. These mines and claims included the Amelia, Bitters, Kates or Norris, Kenna, Kentucky Flat, Morgan, Novis, Tiedemann and Wilton.