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Trinity County


  • Trinity County Granite and Limestone (circa 1906) – Excerpt from The Structural and Industrial Materials of California, Bulletin No. 38, California, State Mining Bureau, San Francisco, California, 1906.

    “The granite in Trinity County is the same material and occurs in the same manner as in Shasta County.

    “In Rush Creek, in Sec 26, T. 34 N., R. 9 W., M. D. M., the hard boulders found in the soft mass of weathered granite were formerly quarried by Masterson & Armstrong of Redding, but at present this quarry is abandoned.

    “Better quarries could be opened in the county, provided transportation facilities to bring the material to market were at hand.”

    Limestone is found in many places in Trinity County. There are: (1) A belt of Devonian limestone, showing in separate lenses for over 100 miles, running about parallel with the South Fork of Trinity River from its source to Hoopa Valley, for the most part intimately associated with igneous rocks; (2) A parallel belt of Devonian limestone running to the northeast of the preceding; and (3) A belt of Carboniferous limestone, entering Trinity County from the southeast near the Hall City mine, in the northeast corner of T. 29 N., R. 10 W., M. D. M., running northwest along the Hayford River, disappearing north of Hayfork and showing farther north on New River, near Patterson’s. (See J. S. Diller, American Journal of Science, 4 th Series, Vol. 15, pp. 342 et seq.) Northeast of these belts numerous limestone exposures are found. The great amount of metamorphism in Trinity County has altered much of the limestone into marble.

  • Trinity County Mines and Mineral Resources (circa 1913-1914) – Excerpts from Report XIV of the State Mineralogist – Mines and Mineral Resources of Portions of California, Chapters of State Mineralogist’s Report – Biennial Period 1913-1914, Part VI. “The Counties of Shasta, Siskiyou, Trinity,” by G. Chester Brown, Field Assistant (field work in October, 1913), San Francisco, California, July, 1915, California State Mining Bureau, San Francisco, California, 1916, pp. 746-925.

    Introduction (to Trinity County)

    “Trinity County, with an area of 3000 square miles, is bounded on the north by Siskiyou, on the east by Shasta and Tehama, on the south by Mendocino, and on the west by Humboldt County, and is drained by the Trinity, Mad, Eel and Van Dusen rivers.

    “Trinity is a mountainous county, its eastern third being covered by the Coast Range, or Trinity Mountains, the summit of which divides it from Tehama and Shasta counties. The mountain ranges of Scott and Salmon on the north form the boundary between it and Siskiyou. Bully Choop, Baldy and other peaks in the Trinity and Salmon Mountain ranges reach an altitude of over 6000 feet. The hydrography of this county is very simple, the Trinity River and its confluents draining all parts of it. This river, heading in the Scott Mountain division of the Coast Range, after flowing south for 60 miles, makes a detour to the northwest, which course it holds for another 60 miles, and united with the Klamath River, in Humboldt County. From the section where Coffee Creek, one of the tributaries, flows into the Trinity, the great banks of auriferous gravel commence, parallel with the present river as far as Swift Creek, in Sec. 9, T. 36 N., R 7. W. The river formerly flowed west of the town of Trinity Center, at an elevation of several hundred feet above its present channel, thence taking a southwesterly course through the Buckeye Range (T. 34 N. R. 9 W.), on to Weaver Basin.

    Through this section, Trinity Center to Weaver Basin, is presented the only evidence of ancient river channels, the ancient river emptying into a great lake at the present Weaver Basin. The material filling this channel is composed of volcanic breccia and rocks of all formations and ages – angular, irregular, rounded and intermingled with conglomerates, clay and sands.

    “The bed of Weaver Basin is a cement, several hundred feet in thickness below the auriferous gravel, deposited from the ferruginous, siliceous and calcareous matter carried down by the waters, erosions of the various formations along the channel settling in the basin, and there cementing. The absence of coarse material leads to the hypothesis that this cementation took place prior to the filling of the cement channel with auriferous sands and gravel.

    “Bibl.: Bull. No. 540, pp. 16-18, U.S.G.S.

    Geology (of Trinity County)

    “Scott Mountain, formed of igneous, volcanic rocks, with its showing of basalts, trachyte, and obsidian, overlaps the granite as shown in the Salmon Range to the west, its gray peaks towering above the timber line into the region of perpetual snow. On the east is the Trinity Range of granite, syenites, diabase and porphyries. Farther south on the range are metamorphic gneiss, hornblende and mica schists, then a slate belt, followed by a large belt of serpentine crossing in T. 38 N., R. 5 W.

    History (of Trinity County)

    “The first discovery of mineral in this county is attributed to Major Redding, in 1848, who prospected the Trinity River near Redding Creek (T. 32 N., R. 10 W.), and following his discovery came the prospectors from all sections, working the river bars, the ravines and gulches, extracting the gold from the gravel and sands by the rocker, tom and sluice. The evidence of these early workings can be seen along the course of almost every streamlet, creek, gulch and ravine tributary to the Trinity.

    Mining Conditions (in Trinity County)

    “While Trinity County is lacking in railway facilities, the abundance of timber and water overcomes this handicap to a large extent.

    “Gold mining has been the principal industry for over fifty years, the placers giving Trinity County its wealth, and there are still many hundreds of acres of auriferous gravel awaiting exploration. Dredge mining is being successfully pursued at Trinity Center and Lewiston , and large areas in both these districts have recently been prospected for their dredging possibilities (circa 1913).

    “The La Grange, the largest active hydraulic mine in the world; is in this county.

    “Quartz mining is still in its infancy; quartz veins, carrying gold, are being prospected and worked in different sections; others that have been operated for several years have yielded and some are still yielding handsome returns to the owners; Dedrick, and the North and East Forks are the most active quartz districts at the present time (circa 1913), due to the installing of machinery and the development work on the Globe and Craig mines in the former section, and to the number of prospects being opened up in the North and East Fork territory.

    “The Brown Bear is the best known quartz mine in the county, and at one time was the largest producer.

    Mineral Resources (in Trinity County)

    “Its mineral resources consist of gold, silver, platinum, quicksilver, chromic iron, coal, copper, building stone and asbestos. The government records show a total mineral production at $150,000,000. Mineral production of Trinity County, from 1894 to 1913, inclusive, from records of California State Mining Bureau are as follows:

    Chart Page 875
    Chart Page 876
    Page 875
    Page 876

    Electrical Power Plants (in Trinity County)

    “Humboldt Gas & Electric Company, with its generating plants about one mile northwest of Junction City, on the Trinity River, serves the territory on its line between this town and Eureka, Humboldt County.

    “Trinity Gold Mining & Reduction Company has a 700 horsepower plant on Coffee Creek and supplies power to the Alta Bert Dredging Company, and to its own property, the Headlight Mine, near Trinity Center.

    Trinity Gold Dredge Company, with a 1500 horsepower plant, on Stewart’s Fork, supplies power for operating its dredge at Lewiston .

    The Bonanza King, generating plant, on the south fork of the Trinity River, supplies electricity for the mine and for the town of Trinity Center.”

    Granite (in Trinity County)

    “The granite in Trinity County is principally a hornblende granite, and where not decomposed generally shows the effect of strong pressure. These fracture planes and the quartz seams cutting through the rock render much of it unfit for commercial use….”

    Limestone (in Trinity County)

    “Limestone is found in many places in this county, a belt of Devonian limestone, associated with igneous rocks, is found running parallel with the South Fork of the Trinity River from its source to Hoopa Valley; also a parallel belt of Devonian limestone running to the northeast of the preceding and another belt of Carboniferous limestone entering Trinity from the southeast in T. 29 N., R. 10 W., running northwest along Hay Fork River, disappearing north of Hay Fork and showing farther north on New River.

    “Bibl.: Bull. No. 38, p. 94; Diller-American Journal of Science, 4 th Series, Vol. 15, p. 342.”

    Marble (in Trinity County)

    “Outcrops of gray marble occur near the mouth of East Fork and near Taylor’s Flat, in the Big Bar mining district; deposit has not been worked and its extent not determined (circa 1913).

    “Bibl.: Report XIII, p. 633.”

    Ornamental Stones (in Trinity County)

    “A prominent belt of jasper occurs on the divide between the north fork of Trinity River and the east fork of the north fork, showing especially in Secs. 5 and 8, T. 35 N., R. 11 W., M.D.M.

    “Another belt is found on Red Mountain, at the head of Prospect Creek, in the southwest corner of T. 29 N., and in northwest corner of T. 28, N., R. 11 W., M.D.M.

    Garnet is found in the vicinity of Carrville. Discovered in 1899 by G. L. Carr; richly colored ouvaroite (lime-chrome garnet) in small dodecahedral crystals from 1 to 3 millimeters in diameter, deep green in color, coating seams or cavities in chrome iron.

    “Bibl. Bull. No. 37, pp. 39, 53.”

    Soapstone (in Trinity County)

    “Soapstone is found on Brown’s Mountain, in Sec. 21, T. 33 N., R. 9 W., M.D.M., the croppings have a light gray color. It does not weather nor harden when exposed to the air. When put in the fire it does not disintegrate, and is used as fireproof material in fireplaces.

    “Bibl.: Bull. No. 38, pp. 353, 371.”

  • Trinity County, California, Mineral Resources & Introduction to the Trinity County Area of California (circa 1915) – Excerpt from Sacramento Valley and Foothill Counties of California: An Illustrated Description of all the Counties Embraced in this Richly productive Geographical Subdivision of the Golden State, compiled and edited by Emmett Phillips and John H. Miller, Published under the direction of The Sacramento Valley Exposition, J. A. Filcher, Director-in Chief, January, 1915.

    Trinity County

    “Trinity County is situated in the Coast Range Mountains, just east of the northern end of the Sacramento Valley and is drained and watered by the Trinity, Mad, Eel and Van Dusen Rivers. It is a mountainous region, its hills and peaks ranging in altitude from Woodland Scene in Trinity County
    Woodland Scene
    in Trinity County
    a few hundred to more than 9,000 feet. Through these hills and mountains flow numerous streams, nearly all of which are a part of the watershed of the Trinity River, which rises in the northern and eastern part of the county, and leaving the county’s confines, empties into the Klamath River.

    “Mining has been the principal industry of the county for more than fifty years. Other industries are farming, grazing and lumbering. Hydraulic, placer, drift, dredge and quartz mining are all followed with profitable results and there are still hundreds of acres of auriferous gravel awaiting exploration and many quartz veins that are untouched. Hydraulic mining is vigorously prosecuted in various parts of the county under conditions which enable that branch of mining to be conducted more advantageously than in any other part of the State. The placer grounds are so situated that the debris from their workings passes into the Trinity and finally into the Klamath River, which are unnavigable and hence are not injured by the operations. The heavy grade of the streams, the abundant rainfall, the heavy depths of snow in the high mountains, the temperate climate, the abundance of timber and the favorable character of the gold bearing gravel, make Trinity ideal for the hydraulic miner.

    “A number of the best equipped and among the largest hydraulic mines in the world are in operation in this county. A great many mines have been constantly worked with favorable results for many years. The large bodies of undeveloped ground present a promising field for investment. Ledges of gold bearing ores have been discovered at nearly every point where paying gravels have been worked and new prospects are being constantly found in various parts of the county. Improved methods of working and milling have attracted attention to bodies of low grade ore not regarded formerly as profitable. Quartz mining, therefore, is being developed and the county is destined to become one of the leading quartz mining counties in California. As in hydraulic mining, conditions are favorable for quartz mining, there being an abundance of timber and of water and the climatic conditions being favorable.

    “Along the Trinity River and its tributaries are numerous bars of rich gravel. They are at too slight an elevation to be successfully worked by hydraulic method, but offer a successful field for dredge mining. With the aid of electric power, dredge mining promises to take its place in Trinity County with the hydraulic and quartz industries.

    “Extensive bodies of Cinnabar ores have been found and worked in the northern end of the county and Cinnabar has been found near Weaverville and on Cañon Creek.

    “Near Trinity Center, Weaverville and Douglas City, deposits of asbestos have been uncovered. A considerable amount of platinum and iridium is found with the Placer gold in the Hay Fork, Junction City and Lower Trinity districts. Copper ores of high grade values are found in the northern central portions of the county, which give every promise of being developed into extensive and profitable mines.

    “While but little has been done toward the discovery and the working of any minerals other than gold, what has been done justifies further investigation as the prospects are favorable for opening up profitable bodies of valuable minerals.

    “Though Trinity is primarily a mining county, there are large sections of tillable land which with irrigation during the Summer months will produce abundant crops of grasses, hardy fruits, berries and grains. In the lower elevations and particularly along the Trinity River and in the southern end of the county, peaches, pears, plums, apples, apricots and grapes are produced which in flavor, quality and abundance of yield, compare with like fruits produced in any section of California. The soil is adapted for the raising of alfalfa and grains. Vegetables and berries of every variety thrive and there is a home market in the mining districts for everything that is produced.

    “Nuts of all kinds do well – chestnuts, almonds, walnuts, hickory nuts, pecans, in fact all the common ones doing remarkably well.

    “In the southern and western portions of the county olives have been successfully raised.

    “There are excellent opportunities for dairying in the county and stock raising is now carried on in some sections on a large and profitable scale. In the vicinity of Hay Fork, Heyampon and Trinity Valleys there are bodies of fertile, well watered soils. Grasses grow abundantly on these lands and they are well suited to such industries as hog and sheep raising.

    “Stock raising is remunerative and one of the great coming industries. Range land is ample and there are many native grasses. Climatic conditions are favorable and markets are close at hand.

    “Throughout the county there are very extensive bodies of first-class timber and there are numerous small saw mills in operation during the Summer months. Sugar pine, spruce, fir and yellow pine are the principal merchantable woods. In the southern part there is also quite an area of tan bark oaks.

    “Trinity County, owing to its never failing water supply and the steep grades of its water courses, offers great inducements for the construction of electric power plants.

    “The county seat is Weaverville, a picturesque place in the heart of the mountains. The county has a good school system and an efficient corps of teachers.

    One branch of the State Highway passes through the county, connecting the Sacramento Valley with the Coast counties. This road across the mountains is extensively traveled during the Summer months and is one of the scenic driveways of the State.

    “As a Summer camping ground no place in the world can be found to excel this county. Its altitude is all that could be desired, the wonderful scenery, clear running brooks teeming with fish, game to be had with little exertion, the wonderful scenic roads and trails, must be seen to be appreciated, and once seen will never be forgotten.”

  • Trinity County Mineral Industry (circa 1919) – Excerpt from California Mineral Production for 1919, Bulletin No. 88, by Walter W. Bradley, California State Mining Bureau, 1920, pp. 169.
    Area: 3,166 square miles.
    Population
    : 2,551 (1920 census)
    Location
    : Northwestern portion of state.

    “Trinity, like Siskiyou County, requires transportation facilities to further the development of its many and varied mineral resources. Deposits of asbestos, barytes, chromite, copper, gold, mineral water, platinum, quicksilver, silver, and building stone are known here, but with the exception of gold, chromite, copper, and platinum, very little active production of these mineral substances has been made as yet. The 1919 output of $536,783 shows a decrease from the 1918 figure of $707,524, due mainly to chromite and copper.

    “In the twenty-sixth place, commercial production for 1919 was:

    (Headings for the information below are: Substance, Amount, and Value.)

    Gold, —, $500,000 (estimated)
    Silver, ---, $7,500 (estimated)
    Stone, miscellaneous, ---, $11,839
    Other minerals,* ---, $17,444
    (Total value) $536,783

    (* Includes copper, mineral water, platinum, and quicksilver.)

    Trinity County, 1916 Map, from California Mineral Production for 1919 (with County Maps), Bulletin No. 88, by Walter W. Bradley, California State Mining Bureau, San Francisco: California State Printing Office, 1920, pp. 183. Trinity County , 1916 Map
  • Trinity County Limestone Deposits (circa 1947) – Excerpts from “Limestone in California,” by 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. Used with permission, California Department of Conservation, California Geological Survey.)

    “Due to distance from railroads of most of Trinity County, there has been little development of the non-metallic minerals and there has never been any detailed investigation of limestone deposits, although these are known to occur in several places. Gold has been the principal mineral product, except in the extreme southwest corner, where the only railroad touching the county passes near an old copper mine which has made considerable production.

    “Some lime was burned for local use from a deposit in sec. 21, T. 33 N., R. 9 W., M.D., and from another at the head of Oregon Gulch in sec. 3, T. 33 N., R. 10 W., M.D.

    “Lenses of coarsely crystalline limestone are common in the Abrams schist, and in the Chanchelulla formation in the eastern part of the county, 50 miles or more west of the railroad. In the region along the South Fork of Trinity River a series of limestone lenses once thought to be Devonian extends for many miles from the head of the river to Humboldt County near Willow Creek. The most accessible of these, in Humboldt County, are 33 miles from the nearest railroad point. Another similar belt lies a little east of the first, and a third series is reported still farther inland, in Paleozoic rocks.”


Trinity County – List of Stone Quarries, Etc. *

(* Please note this list does not include sand or gravel quarries.)

  • Brown Mountain, Trinity County, California – Limestone Quarry & Limekiln (from The Structural and Industrial Materials of California, Bulletin No. 38, California, State Mining Bureau, San Francisco, California, 1906.)

    “On Brown Mountain, in Sec. 21, T. 33 N., R. 9 W., M. D. M., owned by the Southern Pacific Railroad Company, is a belt of limestone having a nearly north and south trend. It was quarried years ago, and burned in a limekiln of which the remnants are still visible. The lime was used in the piers of the bridge formerly crossing Trinity River at Lowden’s and in the Masonry of the courthouse at Weaverville. The limestone is coarsely crystalline. The quarry excavations are shallow and caved in, and it is impossible to determine the size, dip, or bedding of the limestone.”

    • “Brown Mountain, Trinity County, California – Limestone Quarry & Lime Kiln (Limestone) (Excerpt from Report XIV of the State Mineralogist – Mines and Mineral Resources of Portions of California, Chapters of State Mineralogist’s Report – Biennial Period 1913-1914, Part VI. “The Counties of Shasta, Siskiyou, Trinity,” by G. Chester Brown, Field Assistant (field work in October, 1913), California State Mining Bureau, San Francisco, California, 1916, pp. 746-925.)

      On Brown’s Mountain, in Sec. 21, T. 33 N., R. 9 W., M.D.M., a belt of limestone was quarried several years ago and burned in a limekiln, and the product used in the masonry of the courthouse at Weaverville. It is owned by the Southern Pacific Railroad Company.

      “Bibl.: Bull. No. 38, p. 94.”

  • Brown’s Mountain, Trinity County, California – Soapstone Deposit (From The Structural and Industrial Materials of California, Bulletin No. 38, California, State Mining Bureau, San Francisco, California, 1906.)

    “On Brown’s Mountain, in Sec. 21, T. 33 N., R. 9 W., M. D. M., is a cropping of soapstone. The color is light gray, with numerous specks of ochre. Part of the material is steatite. It is obtained by sawing the uncovered blocks, and is used as fireproof material in fireplaces, etc. Apparently, it does not weather on exposure to the air, nor harden. When put in the fire, it does not disintegrate.”

    • Brown’s Mountain, Trinity County, California – Soapstone Quarrying (Soapstone) (Excerpt from Report XIV of the State Mineralogist – Mines and Mineral Resources of Portions of California, Chapters of State Mineralogist’s Report – Biennial Period 1913-1914, Part VI. “The Counties of Shasta, Siskiyou, Trinity,” by G. Chester Brown, Field Assistant (field work in October, 1913), California State Mining Bureau, San Francisco, California, 1916, pp. 746-925.)

      Soapstone is found on Brown’s Mountain, in Sec. 21, T. 33 N., R. 9 W., M.D.M., the croppings have a light gray color. It does not weather nor harden when exposed to the air. When put in the fire it does not disintegrate, and is used as fireproof material in fireplaces.

      “Bibl.: Bull. No. 38, pp. 353, 371.”

  • Hayfork (near), Trinity County, California – Limestone Exposure (from The Structural and Industrial Materials of California, Bulletin No. 38, California, State Mining Bureau, San Francisco, California, 1906.)

    “In the vicinity of Hayfork, in T. 31 N. R. 11 W., M. D. M. (unsurveyed), are found several detached exposures of limestone, which are typical of similar exposures through the county.”

    • Hay Fork Valley, Trinity County, California – Limestone Belt (Limestone) (Excerpt from Report XIV of the State Mineralogist – Mines and Mineral Resources of Portions of California, Chapters of State Mineralogist’s Report – Biennial Period 1913-1914, Part VI. “The Counties of Shasta, Siskiyou, Trinity,” by G. Chester Brown, Field Assistant (field work in October, 1913), California State Mining Bureau, San Francisco, California, 1916, pp. 746-925.)

      “In the Hay Fork Valley, in Secs. 1, 3 and 33, T. 31 N., R. 11 W., M.D.M., a belt of limestone, exposed in places running northwest, is observed.

      “Bibl.: Bull. No. 38, p. 94.”

  • Oregon Gulch, Trinity County, California – Limestone Quarried at the head of Oregon Gulch (from The Structural and Industrial Materials of California, Bulletin No. 38, California, State Mining Bureau, San Francisco, California, 1906.)

    “At the head of Oregon Gulch, in Sec. 3, T. 33 N., R. 10 W., M. D. M., there is a body of limestone from which in 1856 lime was burned, which was used in several buildings in Weaverville.”

    • Oregon Gulch (head of), Trinity County, California – Limestone Deposit (Limestone) (Excerpt from Report XIV of the State Mineralogist – Mines and Mineral Resources of Portions of California, Chapters of State Mineralogist’s Report – Biennial Period 1913-1914, Part VI. “The Counties of Shasta, Siskiyou, Trinity,” by G. Chester Brown, Field Assistant (field work in October, 1913), California State Mining Bureau, San Francisco, California, 1916, pp. 746-925.)

      “A body of limestone, at the head of Oregon Gulch, in Sec. 3, T. 33 N., R. 10 W., M.D.M., was the source of lime in 1856, which was used in the construction of several buildings in Weaverville.

      “Bibl.: Bull. No. 38, p. 94.”

  • Taylor’s Flat (near), Trinity County, California – Marble Outcrop (Marble) (Excerpt from Report XIV of the State Mineralogist – Mines and Mineral Resources of Portions of California, Chapters of State Mineralogist’s Report – Biennial Period 1913-1914, Part VI. “The Counties of Shasta, Siskiyou, Trinity,” by G. Chester Brown, Field Assistant (field work in October, 1913), California State Mining Bureau, San Francisco, California, 1916, pp. 746-925.)

    Outcrops of gray marble occur near the mouth of East Fork and near Taylor’s Flat, in the Big Bar mining district; deposit has not been worked and its extent not determined.

    “Bibl.: Report XIII, p. 633.”

  • Weaverville (east of), Trinity County, California – Rush Creek Granite Quarry (formerly worked by Masterson & Armstrong) (Granite) (Excerpt from Report XIV of the State Mineralogist – Mines and Mineral Resources of Portions of California, Chapters of State Mineralogist’s Report – Biennial Period 1913-1914, Part VI. “The Counties of Shasta, Siskiyou, Trinity,” by G. Chester Brown, Field Assistant (field work in October, 1913), California State Mining Bureau, San Francisco, California, 1916, pp. 746-925.)

    “In the Rush Creek quarry, formerly worked by Masterson & Armstrong, of Redding, the hard boulders found in the soft mass of weathered granite were used for ornamental and monumental purposes. This deposit is in Sec. 26, T. 34 N., R. 9 W., M.D.M., on Rush Creek, 6 miles east of Weaverville, the county seat.

    “Bibl.: Report XII, p. 387; Bull. No. 38, p. 57.”

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