Gold Run District

Past Producer in Placer county in California, United States with commodities Gold, Silver, Platinum

Sections on this page

Identification information
Geographic coordinates
Site location context
Geographic areas
Public Land Survey System information
Commodities
Materials information
Mineral occurrence model information
Host and associated rocks
Nearby scientific data
Geologic structures
Ore body information
Controls for ore emplacement
Economic information about the deposit and operations
Mining district
Land status
Ownership information
Bibliographic references
General comments
Reporter information

Geologic information

Identification information

Deposit ID	10310621
Record type	District
Current site name	Gold Run District

Comments on the site identification

The Gold Run District is in north-central Placer County, south of the town of Gold Run. The district produced from extensive auriferous Teriary placer gravels deposited by an ancestral American River.

Geographic coordinates

Geographic coordinates:	-120.84903, 39.16389 (WGS84)
Elevation	850
Relative position	Two miles southwest of Dutch Flat

Site location context

Political divisions (FIPS codes)

Placer(county)

California(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Dutch Flat(quadrangle 1:24,000 scale)

Truckee(quadrangle 1:100,000 scale)

Chico(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

North Fork American(hydrologic unit)

Lower Sacramento(hydrologic accounting unit)

Sacramento(hydrologic subregion)

California(hydrologic region)

Geographic areas

Country	State	County
United States	California	Placer

Public Land Survey System information

Meridian	Township	Range	Section	Fraction	State
Mount Diablo	015N	010E	3,4,9,10,15,16		California

Comments on the location information

Location selected for latitude and longitude is the approximate center of the main Gold Run hydraulic workings in section 9-T15N-R10E as shown on the USGS 7 1/2-minute Dutch Flat quadrangle

Commodities

Commodity	Importance
Gold	Primary
Silver	Secondary
Platinum Critical	Secondary

Comments on the commodity information

Commodity Info: Average value of upper gravels = $0.08 per cubic yard.
Average value of lower gravels = $0.30 per cubic yard.
Lower gravels yielded as much as $9.00 per cubic yard.

(all prices at $35.00 gold)
Ore Materials: Native gold - Fine -coarse gold and nuggets (.900 fine)
Gangue Materials: Quartz and metamorphic gravels; accessory minerals magnetite, ilmenite, zircon, pyrite, amphibole, epidote, chlorite, and siderite

Materials information

Materials	Type of material
Gold	Ore
Quartz	Gangue
Magnetite	Gangue
Ilmenite	Gangue
Zircon	Gangue
Pyrite	Gangue
Amphibole	Gangue
Epidote	Gangue
Chlorite	Gangue
Siderite	Gangue

Mineral occurrence model information

Model code	119
USGS model code	39a
Deposit model name	Placer Au-PGE
Mark3 model number	54

Host and associated rocks

Host or associated Host

Rock type Unconsolidated Deposit > Sand and Gravel

Stratigraphic age (youngest) Tertiary

Nearby scientific data

(1)	-120.84903, 39.16389	ListMap

Economic information

Geologic structures

Type of structure	Local
Structure description	Foresthill Fault
Type of structure	Regional
Structure description	Melones Fault Zone, Foresthill Fault, Gills Hill Fault

Ore body information

General form Irregular

General form	Irregular

Controls for ore emplacement

Mechanical accumulation on irregular bedrock riffles and within river- and stream-channel lag gravels, bars, and point bar deposits

Comments on the geologic information

REGIONAL SETTING

The northern Sierra Nevada is home to numerous important gold deposits. These include the famous lode districts of Johnsville, Alleghany, Sierra City, Grass Valley, and Nevada City as well as the famous placer districts of North Bloomfield, North Columbia, Cherokee, Foresthill, Michigan Bluff, Gold Run, and Dutch Flat. The geological and historical diversity of most of these deposits and specific mine operations are covered in numerous publications produced over the years by the U.S. Bureau of Mines, U.S. Geological Survey, California Division of Mines and Geology (now California Geological Survey), and others. The most recent geologic mapping covering the area is the 1:250,000-scale Chico Quadrangle compiled by Saucedo and Wagner (1992).

Stratigraphy

The northern Sierra Nevada basement complex has a history of both oceanic and continental margin tectonics recorded in sequences of oceanic, near continental, and continental volcanism. The complex has been divided into four lithotectonic belts: the Western Belt, Central Belt, Feather River Peridotite Belt, and Eastern Belt.

The Western Belt is composed of the Smartville Complex, an Upper Jurassic volcanic-arc complex, which consists of basaltic to intermediate pillow flows overlain by pyroclastic and volcanoclastic rock units with diabase, metagabbro, and gabbro-diorite intrusives. The Cretaceous Great Valley sequence overlies the belt to the west. To the east it is bounded by the Big Bend-Wolf Creek Fault Zone.

East of the Big Bend-Wolf Creek Fault Zone is the Central Belt, which is in turn bounded to the east by the Goodyears Creek Fault. This belt is structurally and stratigraphically complex and consists of Permian-Triassic argillite, slate, chert, ophiolite, and greenstone of marine origin.

The Feather River Peridotite Belt is also fault-bounded, separating the Central Belt from the rocks of the Eastern Belt for almost 95 miles along the northern Sierra Nevada. It consists largely of Devonian-to-Triassic serpentinized peridotite.

The Eastern Belt, or Northern Sierra Terrane, is separated from the Feather River Peridotite Belt by the Melones Fault Zone. The Northern Sierra Terrane is primarily composed of siliciclastic marine metasedimentary rocks of the Lower Paleozoic Shoo Fly Complex overlain by Devonian-to-Jurassic metavolcanic rocks. Farther east are Mesozoic granitic rocks of the Sierra Nevada Batholith.

The northern Sierra Nevada experienced a long period of Cretaceous to early Tertiary erosion followed by extensive late Oligocene to Pliocene volcanism. The oldest Tertiary deposits are Eocene auriferous gravels deposited by the predecessors of the modern Yuba and American rivers and preserved in paleochannels eroded into basement and on adjacent benches. In contrast to earlier volcanism, Tertiary volcanism was continental, with deposits placed on top of the eroded basement rocks, channel deposits, and Mesozoic intrusives. Two regionally important units are the Valley Springs and Mehrten Formations. The Oligocene-Miocene Valley Springs Formation is a widespread unit of intercalated rhyolite tuffs and intervolcanic channel gravels that blanketed and preserved the basal gravels in the valley bottoms. The younger Miocene-Pliocene Mehrten Formation consists largely of andesitic mudflows, which regionally blanketed all but the highest peaks and marked the end of Tertiary volcanism.

Pliocene-Pleistocene uplift of the Sierra Nevada caused the modern drainages to erode through the volcanic Valley Springs-Mehrten sequences and carve deep river gorges into the underlying basement rocks. During this process, the modern rivers became charged with placer-gold deposits from both newly eroded basement rocks and from the reconcentration of the eroded Tertiary placers. The discovery of these modern Quaternary placers in the American River at Sutter's Mill sparked the California Gold Rush.
Tertiary Channel Gravels

It has been estimated that 40 percent of California's gold production has come from placer deposits along the western Sierra Nevada (Clark, 1966). These placer deposits are divisible into Tertiary deposits preserved on the interstream ridges, and Quaternary deposits associated with present streams. Lindgren (1911) estimated that approximately $507 million (at $35.00/oz.) was produced from the Tertiary gravels. Almost all Tertiary gravel deposits can be divided into coarse basal Eocene gravels resting on basement, and overlying upper or "intervolcanic" gravels. While the gravels differ texturally, compositionally, and in gold values, no distinct contact exists between the two. The boundary is usually placed where pebble and cobble beds are succeeded by overlying pebble, sand, and clay beds.

Lower gravels contain most of the gold and rest on eroded bedrock that is usually smooth, grooved, and polished. Where bedrock is granitic, it is characterized by a smooth and polished surface. Where bedrock is slate, phyllite, or similar metamorphic rock, rock cleavage, joints, and fractures acted as natural riffles to trap fine to coarse gold. In many cases, miners would excavate several feet into bedrock to recover the trapped gold. The lower gravels, or "blue lead," of the early miners are well-cemented and characterized by cobbles to boulders of bluish gray - black slates and phyllites, weathered igneous rocks and quartz. Boulders may range upwards of 10 feet in diameter. In many deposits, disseminated pyrite and pyritic pebble coatings are common in the lower blue lead gravels. Adjacent to the bedrock channels, broad gently sloping benches received shallow but extensive accumulations of auriferous overbank gravels sometimes 1-2 miles wide.

The lower unit is also compositionally immature relative to the upper gravel unit as evidenced by their heavy mineral suites. Chlorite, amphibole, and epidote are common constituents in the basal gravels, but are conspicuously absent in upper gravels.

The upper gravels compose the bulk of most deposits, with a maximum measured thickness of 400 feet in the North Columbia District. These gravels carry much lower gold values (rarely more than a few cents per cubic yard) than the deeper sands and are often barren. Upper gravels are finer grained, with clasts seldom larger than cobble size, and contain abundant silt and clay interbeds. Cross-bedding and cut-and-fill sedimentary structures are abundant as well as pronounced bedding and relatively fair to good sorting. Compositionally they are much more mature, with quartz prevailing, and more stable heavy mineral components consisting almost exclusively of zircon, illmenite, and magnetite. Oxidation is common and often imparts a reddish hue to the gravels.

During the Cretaceous, the Sierra Nevada was eroded and its sediments transported westward by river systems to a Cretaceous marine basin. By the Eocene, low gradients and a high sediment load allowed the valleys to accumulate thick gravel deposits as the drainages meandered over flood plains up to several miles wide developed on the bedrock surface. The major rivers were similar in location, direction of flow, and drainage area to the modern Yuba, American, Mokelumne, Calaveras, Stanislaus, and Tuolumne Rivers. Their auriferous gravels deposits are scattered throughout a belt 40 - 50 miles wide and 150 miles long from Plumas County to Tuolumne County. In the northern counties, continuous lengths of the channels can be traced for as much as 10 miles with interpolated lengths of over 30 miles. The ancient Yuba River was the largest and trended southwest from headwaters in Plumas County. Its gravels are responsible for the placer deposits in the North Bloomfield, San Juan Ridge/North Columbia, Moore's Flat, and French Corral districts. Tributaries to the ancestral Yuba River were responsible for most of the other auriferous gravels in Nevada County.
Bedrock erosion degraded the rich gold-bearing veins and auriferous schists and slates as the rivers crossed the metamorphic belts of the Sierra Nevada. Upstream of the gold belts on the granitic Sierra Nevada batholith, channels are largely barren, but become progressively richer as they cross the metamorphic belt and the Mother Lode trend. They become especially enriched after crossing the gold-bearing "serpentine belt" (Feather River Peridotite Belt) upstream of many Tertiary placer districts. While the most gold is contained in the lower sand and gravel, the majority of rich material is within only a few feet of bedrock. Generally, in drift mines only these lower gravels were exploited; however, in hydraulic mines the whole gravel bed was washed. Lindgren (1911) estimated that on average, the hydraulic washing of thick gravel banks up to 300 feet, including both basal and upper gravels, yielded approximately $0.10 to $0.40/yard. Upper gravels alone might average $0.02 to $0.10/yard and lower gavels from $0.50 to $15/yard or more.

The bulk of the gold in the deposits was derived from gold-bearing quartz veins within the low-grade metamorphic rocks of the Sierra Nevada. Gravels that have the highest gold values contain abundant white quartz vein detritus and clasts of blue-gray siliceous phyllite and slate common to the gold-quartz vein-bearing bedrock of the region. Unusually high gold concentrations have also been documented immediately downstream of eroded qold quartz veins exposed in the scoured bedrock.

Most of the gold found in the gravels of the North Bloomfield and Moore's Flat districts is thought to have originated from the famous lode veins of the Alleghany Mining District. The veins in the Nevada City and Grass Valley districts have been proposed as possible sources for the gold in the gravels of the Sailor Flat and Blue Tent diggings.

Gold particles tend to be flat or rounded, shiny and rough, and range from fine and coarse gold to nuggets of 100 or more ounces. Large nuggets were especially prevalent in the Alleghany, North Columbia, Downieville, and Sierra City Districts. The gold particles are almost everywhere associated with black sands composed of magnetite, ilmenite, chromite, zircon, garnet, pyrite, and in some places platinum. Fine flour gold is not abundant in any of the Tertiary gravels. Lindgren (1911) and others have suggested that most of the flour gold was swept westward to be deposited in the thick sediments of the Great Valley.

Valley Springs Formation

After deposition of the Eocene channel gravels, Oligocene-Miocene volcanic activity in the upper Sierra Nevada radically changed drainage patterns and sedimentation. The first of many eruptive rhyolite flows filled the depressions of most river courses covering the Eocene gravels and diverting the rivers. Many tributaries were dammed, but they eventually breached the barriers and carved their own channels within the rhyolite fill. Ensuing intermittent volcanism caused recurrent rhyolite flows to fill and refill the younger channels resulting in a thick sequence of intercalated intervolcanic channel gravels and volcanic flows. In the Scotts Flat District, very little of the Valley Springs Formation remains, having been lost to erosion.

Mehrten Formation

Volcanism continued through the Oligocene to the Pliocene, with a change from rhyolitic to andesitic composition and a successively greater number of flows. During the Miocene and Pliocene, volcanism was so extensive that thick beds of andesitic tuffs and mudflows of the Mehrten Formation blanketed the Valley Springs. Thicknesses ranged from a few hundred to a few thousand feet. Pleistocene erosion removed much of these deposits, but remnants cap the axes of many existing ridges at mid-elevations.
Continued uplift during the Pliocene-early Pleistocene increased gradients allowing the modern drainages to cut through the volcanic mantle and auriferous gravel deposits and deeply into basement. The once-buried Tertiary river gravels were left exposed in outcrops high on the flanks of the modern drainage divides.

Structure

Most Upper Jurassic and younger basement rocks of the northern Sierra Nevada were metamorphosed and deformed during the Jurassic-Cretaceous Nevadan Orogeny. The dominant northwest-trending structural grain is a result of this period of compressive deformation, which produced thrust faults, major northwest-trending folds, and regional greenschist facies metamorphism. This episode also resulted in intrusions of granitic plutons that formed the Sierra Nevada.

Nevadan deformation structures within and between the northern Sierra Nevada lithotectonic blocks are steeply dipping northwesterly trending faults and northwesterly trending folds. These features are best developed in the Eastern, Central, and Feather River Peridotite Belts, where the faults have been collectively described as the "Foothills Fault System" (Clark, 1960). Where the attitude can be determined, most of the bounding faults dip steeply east and display reverse displacement.

The regional northwest-trending structural grain is also at approximately right angles to the prevailing direction of stream flow of both the ancient and modern channels. This grain, expressed in the form of foliation and cleavage in the metamorphic bedrock, served as a good trapping mechanism for the gold particles.

GEOLOGY OF THE GOLD RUN DISTRICT

Throughout most of the Gold Run District, only the basement rocks of the Calaveras Complex and the overlying Eocene auriferous gravels are present. While thick sections of Oligocene to Pliocene Valley Springs and Mehrten Formation rocks are present to the south in the districts of the Forest Hill Divide, and northwest in the Scotts Flat District, they have been largely lost to erosion at Gold Run.

The main body of basement rocks within the district consists of a belt of north-northwest-trending steeply dipping, slate, argillite, amphibolite, phyllite, chert, and metavolcanic rocks of the Calaveras Complex. Gabbroic and serpentinite intrusions are common. The Foresthill Fault, a steep easterly dipping thrust fault trends north-south through the district and cuts the Calaveras Complex. To the east of the district, the Melones Fault Zone (Clark, 1960) separates the Calaveras Complex from partially to completely serpentinized peridotite of the Feather River Peridotite Belt.

Basal Eocene Auriferous Gravels

Due to localized erosion of the Valley Springs and Mehrten Formations, the Gold Run and neighboring districts were known for their immense bodies of exposed auriferous gravel. The district produced from extensive auriferous channel gravels deposited by a tributary to the Tertiary Yuba River. Pebble imbrication and cross-bedding indicate this tributary flowed northward through the Gold Run District before turning sharply southwest in the neighboring Dutch Flat District. The tributary then flowed southwesterly, crossing the present Bear River about a mile west of Dutch Flat, and then flowed 2-3 miles through the You Bet District where it was mined at the Christmas Hill and Little York Diggings. It then turned sharply north and flowed through the Red Dog and Hunt's Hill areas to its confluence with the Yuba River near North Columbia.
In some places, the Eocene gravels at Gold Run are more than a mile wide in an east-west direction, but average between 600 and 1000 yards wide. They extend for about 4 miles in a north-south direction from Indiana Hill to Dutch Flat. They achieve a maximum thickness of 400 feet and can be divided into lithologically and texturally distinct units. The lower unit, or blue lead of the early miners, rests directly on bedrock, and contains most of the gold, yielding as much as $9/yard. It is generally confined to the wide channel troughs on bedrock and buried under thick sections of upper gravel. Underlying bedrock is slate in the western part of the district and gabbroic rock in the east. Bedrock is in part polished and hummocky with slates being in part soft and decomposed. Upper gravels contain abundant quartz with sand and clay and averaged only 11 to 17 cents per yard. Much of the district output came from the upper gravels in the vast Stewart hydraulic mine, which is currently traversed by Interstate 80. Channel grade was as much as 10 feet in 100 feet in the Gold Run and Dutch Flat area.

The lower gravels are generally immature and composed of bluish-black slate and phyllite of the Calaveras Complex, weathered igneous rocks, and quartz. Chlorite, amphibole, and epidote mineral grains are also common components. Lower gravels are generally well-cemented; they were extensively drift mined in neighboring districts and at the south end of the district where the river canyon exposed the deposit at Indiana Hill.

The upper gravels form the majority of the Eocene gravel deposits and, unlike the lower gravels, are well-exposed in cliffs and bluffs cut into the old river channels. Their thickness varies significantly within the district. These gravels are much finer, with clasts seldom larger than pebble size and characterized by an abundance of clay and silt beds. Large-scale cross-bedding and cut-and-fill features are common. Upper gravels are mature; quartz predominates, and the heavy-mineral content consists almost exclusively of zircon, ilmenite, and magnetite.

Economic information about the deposit and operations

Operation type	Surface-Underground
Development status	Past Producer
Commodity type	Metallic
Significant	Yes
Discovery year	1849

Mining district

District name	Gold Run District

Land status

Ownership category	Private
Area name	Placer County Planning Department

Ownership information

Type Owner

Owner Various private owners

Type	Owner
Owner	Various private owners

Comments on the workings information

Hydraulic Mining

Hydraulic mining methods were first applied in 1852 to the Yankee Jims gravels in the Forest Hill District of central Placer County. Its use and methods quickly evolved to where it was applied to most exposed Tertiary gravel deposits. Hydraulic mining involved directing a powerful stream of high pressure water through large nozzles (called "monitors") at the base of a gravel bank, undercutting it and allowing it to collapse. The loosened gravels were then washed through sluice boxes. The remaining tailings were indiscriminately dumped in the nearest available stream or river. Large banks of low-yield gravel could be economically mined this way. In some cases, adits were driven into the exposed face and loaded with explosives to help break down the exposure. One of hydraulic mining's highest costs was in the ditches, flumes, and reservoirs needed to supply sufficient volumes of water at high pressure. A mine might have many miles of ditches as well as dams and reservoirs, flumes, and tunnels. Hydraulic mining flourished for about 30 years until the mid-1880s when the Sawyer Decision essentially brought it to a halt.

Drift Mining

While limited mining of the Tertiary channel gravels by means of shafts and adits commenced soon after their discovery, underground mining flourished after the Sawyer Decision. Drift mining involved driving adits and tunnels along or close to the lowest point in the bedrock trough of an ancient channel and following it upstream along the bedrock surface. Some deeply buried drift mines were originally accessed through vertical shafts requiring timbering, headframes, hoisting, and pumping equipment. Larger shafts were seldom over 3 compartments Smaller mines often had single compartment shafts as small as 2 x 5 feet. Since considerable water was associated with the gravels, it was a serious problem in deeper shafts and costly pumping was required. By the 1890s, due to drainage problems and the expense of hoisting, most major drift mines were accessed through tramway and drain tunnels driven into bedrock below the channels.

Channels were usually located by gravel exposures on hillsides and terraces. Exposures of upstream and downstream gravels were called "inlets" and "outlets," respectively. Where a ravine or canyon cut into, but not through an old channel, the exposure was called a "breakout."

The preferred method of developing an inlet was to tunnel through bedrock under the channel at such a depth and angle as to break through into the bed of the channel providing natural drainage. The overlying gravels could then be accessed directly through the tunnel or by periodic raises and drifts. Development of an outlet involved following the bedrock channel directly into the hillside, the incline of the bedrock providing natural drainage. The tunnel entrances were usually in or near a ravine or gulch to aid in waste-rock disposal.

Prospecting and developing a breakout was more difficult, since the exposed gravel could be in the basal channel or hundreds of feet up on the edge of the channel, making it impossible to locate a prospect tunnel with any certainty. The surest method of prospecting was to run an incline on the pitch of the bedrock. Another method was to sink a vertical shaft on the presumed channel axis. The former method proved superior since it involved less subjectivity and often uncovered paying bench gravels on edges of the old stream. Once the bed of the channel was located, it was prospected by drifts and cross cuts to ascertain width, direction, grade, and the location, extent, and quality of pay.

Prospecting also included projecting the grade and direction of existing channel segments for distances up to several miles. Thus having determined a potential location, a prospect adit or shaft was driven to evaluate it. This was a common method of finding old channels where there were no surface exposures.
Access tunnels were driven in bedrock to minimize timbering and ensure a stable roof, through which upraises were driven to work the placer gravels. Tunnels were generally run under the lowest point of the bed of the channel in order to assure natural drainage and to make it possible to take auriferous gravels out of the mine without having to hoist it.

The main drifts were kept as straight as possible and in the center or lowest depression of the channel. To prospect the width of the channel, crosscuts at right angles to the drift were driven on each side to the rims of the channels or the limit of the paying lead. These were timbered and lagged in soft gravels, but not to the extent of the main drift. In wide pay leads, gangways paralleled the main tunnel to help block out the ore in rectangular blocks. In looser gravels, timbering was required and the main difficulty was preventing caving until timbering was in place. The looser gravels were excavated with pick and shovel. Up until the late 1800s, most workings were driven by hand, then later by machine and pneumatic drills.

Working drifts in the gravel beds and pay leads themselves were larger than the bedrock tunnels and usually timbered due to their extended and long-term use. In wide gravel deposits, as a precaution against caving, gravel pillars from 20 - 40 feet wide were left on each side of the drift. When the main access tunnel was in bedrock following the line of the channel, pillars were not required, as the tunnel in the gravel was only for temporary use in mining the ground between its connections with the bedrock tunnel. Raises to access the gravel were made every 200 - 400 feet as necessary.

The breaking out of gravel (breasting) was done from the working faces of drifts. Usually, 1-2 feet of soft bedrock and 3-4 feet of gravel were mined out to advance the face. When the gravels were well-cemented, blasting was required. Otherwise the material could be removed with picks. Boulder sized material was left underground and only the gravels and fines were removed from the mine.

Bedrock swelling was a frequent problem. Tunnels on and within bedrock were sometimes affected by the upward swelling of the bedrock. In these cases, heavy timbering was required and the tunnel floor had to be periodically cut and lowered to keep the tunnel open.

Soft or fractured slates were the most favorable bedrock. The surface was usually creviced and weathered enough that gold could be found to a depth of 1 foot in the top of the bedrock. Where sufficiently weathered and soft, this upper bedrock layer could be easily removed. If the surface of the bedrock was too hard to be worked, it was cleaned thoroughly, and the crevices and surface were worked with special tools to remove every particle of gold.

According to the gravel's hardness, they were either washed through sluices or crushed in stamp mills. Much of the gravel was so highly cemented it had to be milled several times. Stamp mills with coarse screens were also found to be suitable for milling cemented gravel. For soft and uncemented gravels, a dump, sluices, and water supply under generally low pressure comprised the entire surface workings.

Ventilation of mines was accomplished by direct surface connection through the use of boreholes and the mine shafts and tunnels. It relied on natural drafts, drafts by fire, falling water, or blowers. Within the mines, arrangements of doors were often used to direct the flow of air through the tunnels, drifts, and breasts.

Ore was removed by ore cars of various capacity determined by available power and tunnel size. In smaller mines, small cars were often pushed by hand. In larger mines using horsepower or trains, larger two ton cars could be brought out in trains of 5-10 cars.

Comments on other economic factors

Economic Comments
The best estimate of production from the Gold Run District is only approximate since old mines had very few estimates of gravel produced. Evidence given by government investigators (1891) indicate 84,750,000 yards had been mined. The later and more careful work of Gilbert in 1908 led him to believe the earlier figures should be increased by 51%. If this correction is applied to the Gold Run District it would indicate a total of about 128,000,000 yards removed. Unfortunately there are no good estimates of yield. Estimates of average yield have ranged from $4.82/ton for the upper low grade gravels. Other estimates for unspecified gravel grades range from $0.08 - $0.15/ton.

Comments on development

Placer mining in the Gold Run District commenced in 1849, and the town of Gold Run was founded in 1854. The town was originally called Mountain Springs. From 1865 to 1878 approximately $6,125,000 in gold was shipped from the express office in town (Clark, 1970). The town thrived due to the extensive neighboring hydraulic mining operations until the mid-1880s when the Sawyer Decision curtailed hydraulic mining debris disposal.

The early mining claims of this district were worked by about 40 small companies, but in later years they came under the ownership of few larger companies, of which Stewart Gravel Mines was the largest. Other large operators were Nicholls Estate Company, J.L Gould, and the Gold Run Ditch & Mining Company.

By 1873, the Gold Run deposits had been worked down to a level where the natural outlets were becoming choked with tailings. A 4,000-foot bedrock drain tunnel was constructed to allow working of lower deposits. Little has been recorded concerning the later hydraulic mining, but one run of 60 days resulted in a production of $64,564.81 from 237,400 yards of the cemented bottom gravel in a place not previously drifted. This yielded an average $0.27/yard for a depth of 80 feet, where considerable dynamite and black powder were used for blasting and 2000 miners inches of water under 450 feet of head was employed.

The cemented "blue lead" gravels occupying the deep trough under the huge deposit of loose and finer material worked by hydraulic mining was extensively drift mined from the south end of the district at Indiana Hill where the river canyon exposed the deposit. The Indiana Hill Blue Gravel Mining Company worked these deposits from 1854. They erected an 8-stamp mill for crushing the cemented gravel in 1864. Between 1872-1874, the company produced 19,997 carloads, which yielded $75,422.47 or an average $4.71/ton. By 1874, the company was working the bottom gravel by drifting through an adit then 1,600 feet long. They were then breasting a face 110 feet wide and taking out from 6-7 feet of gravel inclusive of the bedrock picking. They employed 25 men who extracted from 40-50 1,600 pound carloads every 24 hours. In places, a height of 10 feet was breasted. The previous production of the claim was estimated at $125,000. Between December 1, 1874 and August 21, 1875 the Indiana Hill Cement Mill and Mining Company produced $56,446.47 at an operating cost of $24,000. From 1876 to the end of January 1879, Indiana Hill Placer Mine produced $152,225.90. Details of later production are lacking, but the total is reported to be about $750,000 for the Indiana Hill mines.

In 1911, James Stewart acquired much of the property and did some underground drifting. Mining on a moderate scale continued at Gold Run until about 1915, with considerable production reported in 1908. Minor work was conducted on the deposits in the 1920s and 1930s.

As of 1936, 1,000 feet of the main Gold Run channel bottom had been worked entirely to bedrock beginning at the lower end of Indiana Hill, and a surface pit about 1,600 feet long by 2,000 feet was worked out completely. In addition, most of the top gravel is gone from the rest of the claims and the bottom has been drifted to an extent not exactly known. The upper gravel was ideal for hydraulicking, with no overburden or very large boulders.

Reference information

Bibliographic references

Deposit

Clark, L. D., 1960, Foothills fault system, western Sierra Nevada, California: Geological Society of America Bulletin, v. 71, p. 483-496.
Deposit

Clark, W.B., 1970, Gold districts of California: California Division of Mines and Geology Bulletin 193, p. 52.
Deposit

Hobson, J.B., 1890, Gold Run district; California State Mining Bureau Report 10, p. 427.
Deposit

Jarman, A, 1927, Gold Run: California State Mining Bureau Report 23, p. 81-86.
Deposit

Lindgren, W., 1900, Colfax Folio: U.S. Geological Survey Atlas of the U.S., Folio 66, 10 p.
Deposit

Lindgren, W., 1911, Tertiary gravels of the Sierra Nevada: U.S. Geological Survey Professional Paper 73, p. 144-146.
Deposit

Saucedo, G. J. and Wagner, D. L., 1992, Geologic map of the Chico Quadrangle: California Division of Mines and Geology Regional Map Series Map No. 7A, scale 1:250,000.
Deposit

Yeend, W.E., 1974, Gold-bearing gravel of the ancestral Yuba River, Sierra Nevada, California: U.S. Geological Survey Professional Paper 772, 44 p.

General comments

Subject category	Comment text
Deposit	Due to localized erosion of the Valley Springs and Mehrten Formations, the Gold Run and neighboring districts were known for their immense bodies of exposed auriferous gravel. The district produced from extensive auriferous channel gravels deposited by a tributary to the Tertiary Yuba River. Pebble imbrication and cross-bedding indicate this tributary flowed northward through the Gold Run District before turning sharply southwest in the neighboring Dutch Flat District. In some places, the Eocene gravels at Gold Run are more than a mile wide in an east-west direction, but average between 600 and 1000 yards wide. They extend for about 4 miles in a north-south direction from Indiana Hill to Dutch Flat. They achieve a maximum thickness of 400 feet and can be divided into lithologically and texturally distinct units. The lower unit, or blue lead of the early miners, rests directly on bedrock, and contains most of the gold. The lower gravels are generally well-cemented and immature, composed of bluish-black slate and phyllite of the Calaveras Complex, weathered igneous rocks, and quartz. The upper gravels, which form the majority of the Eocene gravel deposits in this district, are of varying thickness, much finer, and mature. Quartz predominates, and the heavy-mineral content consists almost exclusively of zircon, ilmenite, and magnetite.

Subject category

Comment text

Deposit

Due to localized erosion of the Valley Springs and Mehrten Formations, the Gold Run and neighboring districts were known for their immense bodies of exposed auriferous gravel. The district produced from extensive auriferous channel gravels deposited by a tributary to the Tertiary Yuba River. Pebble imbrication and cross-bedding indicate this tributary flowed northward through the Gold Run District before turning sharply southwest in the neighboring Dutch Flat District. In some places, the Eocene gravels at Gold Run are more than a mile wide in an east-west direction, but average between 600 and 1000 yards wide. They extend for about 4 miles in a north-south direction from Indiana Hill to Dutch Flat. They achieve a maximum thickness of 400 feet and can be divided into lithologically and texturally distinct units. The lower unit, or blue lead of the early miners, rests directly on bedrock, and contains most of the gold. The lower gravels are generally well-cemented and immature, composed of bluish-black slate and phyllite of the Calaveras Complex, weathered igneous rocks, and quartz. The upper gravels, which form the majority of the Eocene gravel deposits in this district, are of varying thickness, much finer, and mature. Quartz predominates, and the heavy-mineral content consists almost exclusively of zircon, ilmenite, and magnetite.

Reporter information

Type	Date	Name	Affiliation	Comment
Reporter	10-SEP-2004	Downey, Cameron (Higgins, Chris, T.)	California Geological Survey CGS (Formerly CDMG)
Editor	01-SEP-2007	Schruben, Paul G.	U.S. Geological Survey	Converted from S&A FileMaker format to Oracle. Edit checks on rocks, units, and ages with Geolex search, and other fields.

Beyond USGS

Supplemental information added by qvyshift.com. Not part of the original USGS MRDS record.

Maps centered on this site

Authoritative California resources

These are landing pages for further research — the state agencies don't currently expose per-mine deep links.