HISTORIC CONTEXT

aka Baldy Mountain

Located about 23 miles northwest of Dillon and about 4 miles south-southeast of Polaris, the Bald or Baldy Mountain district centers around Baldy Mountain, the southernmost mountain in the Pioneer range. Placers were worked as early as 1869 on Dyer (Dyce) Creek, a south-flowing tributary of Grasshopper Creek, the most profitable year being 1908 when 100 ounces of gold were recovered from sluices (Geach 1972; Lyden 1948; Winchell 1914; Corry 1933).

Rocks in the area range in age from pre-Cambrian (Beltian), to Cenezoic, with the principal formations being Paleozoic, Mesozoic and early Cenezoic. The region was the site of intermittent deposition, chiefly in marine waters until Mesozoic times. In Cretaceous times the whole mass of sediments was slowly uplifted and folded. Late in the Cretaceous or early in the Eocene, igneous intrusion resulted in the placement of the Mt. Torrey batholith. In the Bald Mountain area this accomplished the metamorphism of some of the sediments and mineralization during the later phases of the intrusion. The Cenozoic is marked by long-continued erosion, resulting in the dissection of the raised range, exposure of the batholith and the enrichment of ores through weathering.

The area is characterized by the high relief topography of the Pioneer Range which has been carved by glaciers to form glacial valleys and cirques. Placer gold appears to originate in the quartz-gold vein in the felsite deposits above the gulch. Veins occur as strong, persistent bodies, comparatively wide and of tabular form, or in numerous intersecting veinlets in shear zones. Veins in limestone show considerable replacement of the wall rock. Ore is also found in contact and replacement deposits and disseminations in dikes. The ore is simple, consisting primarily of auriferous pyrite, limonite, or hematite with some sylvanite, gold telluride, or native gold (Corry 1933; Sahinen 1935).

The North Star mine was the first mine to be discovered in the Bald Mountain district. On March 16, 1864 A. Sullivan and A. L. Crouse discovered the mineral prospect. However, this mine location did not lead to a general development of the district.

The Old Faithful and Rothchild lodes were discovered on Dyce Creek by A. H. Odell in 1870. Odell treated the ore at the site in an arrastra which was mentioned as being still in use as late as 1891. The mine provided the first silver ore production in the district from 1876 to 1885. In 1892 the Dillon Mining Company built a 25-stamp mill to reduce the ore from the Dillon Mine. The company also worked the Old Faithful, Cable, Alice, Capital and New York mines. It was said in the 1930s that the district had not been thoroughly prospected and that "it is unlikely that the gold resources have been exhausted". In 1951 tungsten ore was found on the Little Hawk claim. By 1955 the Little Hawk Mining Company had erected a 150-ton mill to work the ore, but the deposit proved too low of a grade to operate profitably (Corry 1933; Geach 1972).

The majority of the district's production occurred prior to the the turn of the century before accurate records were taken. The Emerald Mine alone produced 1800 ounces of silver in 1875. The district produced $8,000 in 1880 and $51,000 in 1885. From 1902 to 1965 the district produced only 1,324 tons of ore. Half of the ore production occurred in 1939 and 1940 while three quarters of the gold recovered came from those peak years. In the Twentieth century up to 1965, the district yielded 348 ounces of gold, 3,418 ounces of silver, 4,986 pounds of copper, 80,901 pounds of lead, and 6,700 pounds of zinc. The aggregate value of the metals recovered was only $27,479 (Corry 1933; Sassman 1941; Geach 1972).

Other mines in the district include the Belle, Dement,Grundy, and Grizzly Bear (Sassman 1941).

BOUNDARIES OF THE DISTRICT

Sahinen (1935) states that the Bald Mountain district is at the south end of the Pioneer Range and that it is drained by Grasshopper Creek which flows through Bannack. Geach (1972), who calls the district the Baldy Mountain district, further refines the definition by stating that the district is that land between Grasshopper and Taylor Creeks, taking the region drained by Scudder, Dyce, and Taylor Creeks. Sassman (1941) places the mines of the Bald Mountain district on the southern slopes of Bald Mountain and along Dias (also Dyce or Dyers) Creek. Figure 1 shows the district as defined by Sahinen (1935) and Geach (1972).

HISTORIES OF SELECTED MINES

Cable

The Cable mine is located just above the Old Faithful and adjoins the Capitol claim to the southwest. The mine is a striking example of a fissure vein, filling joints and shrinkage cracks . Limestone country rock is traversed by several remarkably persistent joint systems; in one of which a vein of gold-bearing pyrite was deposited. Ore samples taken 45 feet from the adit portal assayed almost 5 percent copper, .35 ounces per ton silver and .006 ounces per ton gold. The vein pinches out 130 feet from the adit portal while the adit continues on another 40 feet. There is no record of production (Geach 1972; Corry 1933).

Dillon

The Dillon mine is located in the center of section 23, T6S, R12W and can be reached by a road up the East Fork of Dyce Creek. Active in the 1890s, the mine was purchased by A. J. Steele, Phillip Miller, A. B. Clements, D. G. Linn, W. A. Little, Judge Bach, Charles S. Jackman and others for $15,000. These men formed the Dillon Mining Company which built a 25-ton mill on the site in 1892. Miller was superintendent of the work. The mine was developed by a series of inclined shafts, prospect pits and short adits.

The next period of development of the Dillon mine occurred in 1906 when the mine was reopened by A. B. Clements (Sassman 1941).

About 800 feet of combined workings extracted copper ore from a bedding plane vein in the Hasmark Formation near its contact with an underlying quartzite deposit. A sample of the ore taken from a prospect pit near the old incline shaft assayed at 28.68 percent copper, .05 percent lead, .90 percent zinc, with 1.45 ounces of silver and .030 ounces of gold per ton; other samples varied slightly from these figures. Although the early production figures are not available, in 1935, the only year of recorded production, the mine produced 201 tons of ore which yielded 62 ounces of gold, 127 ounces of silver, 1,941 pounds of copper and 974 pounds of lead (Geach 1972).

Emerald

The Emerald mine produced 1800 ounces of silver in 1875. The Mineral Resource index only recorded production in 1875. The mine was reported to be in the West Bald Butte sub-district. The mine was inaccessible by 1935 (WPA

1941; Sahinen 1935; Winchell 1914).

Old Faithful

The Faithful property located in section 24, T6S, R12W is composed of the Faithful, Alice, Capitol, Cable patented claims owned by Mabel Erwin (1972) and the Old Faithful and Sunrise claims owned by Earl Tash (1972). The Old Faithful was the first lode mine in the district and has a long history of intermittent production. It was discovered in 1870 by A. H. Odell, who worked its ore with an arrastra. The

Dillon Tribune

in 1886 reported that the 250 foot incline shaft gave access to 300 feet of underground workings. Veins were worked that ranged from three to five feet in width and produced free-milling gold ore that assayed at $15 to $20 per ton. In 1892 the ore from the Old Faithful, Capitol, Cable and Alice was worked in the mill at the Dillon mine.

The mine was reported in 1894 to be owned and operated by the Faithful Mining Company. The operation employed 15 miners and three top men extracting ore from a 400 foot long adit. The ore was reported to be free-milling (Shoemaker 1894).

However, by 1914 when the mine was described by Winchell, it had not been in production for many years. By 1935, the mine workings were inaccessible. The property was discussed in the mining literature in 1938 and reported renewed production in 1940. This last episode of production continued until 1949 with a hiatus during World War II. Although records of early production are either not available or mixed with the Dillon Mining Company totals, from 1939 to 1949 the Faithful mining properties produced 1,037 tons of ore. This yielded 268 ounces of gold, 1,576 ounces of silver, 2,582 pounds of copper, 6,700 pounds of zinc and 35 tons of lead (Swallow 1891; WPA 1941; Geach 1972; Sahinen 1935; Winchell 1914).

Garrett

The Garrett was one of the early producers, but by 1935 the mine was reported to be inaccessible (WPA

1941; Sahinen 1935; Winchell 1914).

Little Bell

The Little Bell in the Dyer Creek basin was worked on the principal fissures converging toward the south. There is no other further information on this operation (Corry 1933).

Mayflower

The Mayflower is located in section 22 T6S, R12W in the Dyer Creek basin and was worked on the principal fissures converging toward the south. The only production occurred in 1935 and was limited to small amounts taken from shallow prospect pits (Geach 1972; Corry 1933).

North Star

The North Star mine was the first mine to be discovered in the Bald Mountain district. On March 16, 1864 A. Sullivan and A. L. Crouse discovered the mineral prospect. However, this mine location did not lead to a general development of the district.

Orofino

The Orofino mine is located on McMannus Creek and there is little information (Corry 1933).

Vanguard

The Vanguard mine has crystalline pink rhodochrosite gangue. Hydrothermal activity has produced contact -replacements (Corry 1933).

Witherspoon Group

The Witherspoon Group is on the upper basin of Rattlesnake Creek. In it porphyry dikes in granite are bordered by quartz veins containing gold bearing pyrite and other sulphides (Corry 1933).

BIBLIOGRAPHY

Billingsley, Paul and J. A. Grimes

1917 "Ore Deposits of the Boulder Batholith of Montana",

American Institute of Mining and Engineering Bulletin #124

. pp. 641-717.

Corry, Andrew

1933 "Some Gold Deposits in Broadwater, Beaverhead, Phillips, and Fergus Counties, Montana",

Montana Bureau of Mines and Geology

, Memoir 10.

Geach, R. D.

1972 "Mines and Mineral Deposits (except fuels) Beaverhead County, Montana",

Montana Bureau of Mines and Geology, Bulletin 85

.

Hill, James M. and Waldemar Lindgren

1912 "The Mining Districts of the Western United States",

U. S. Geological Survey Bulletin 507

, pp. 181-198, U.S. Government Print. Off., Washington, D. C.

Lyden, Charles J.

1948 "The Gold Placers of Montana",

Montana Bureau of Mines and Geology Memoir 26

. Montana School of Mines, Butte.

Sahinen, Uuno M.

1935 "Mining Districts of Montana", Thesis, Montana School of Mines, Butte.

Shoemaker, C. S.

1894

Fifth Annual Report of the Inspector of Mines of the State of Montana

, Intermountain Publishing Company, Butte.

Swallow, G. C., J. B. Trevarthen and Jacob Oliver

1891

Reports of Inspectors of Mines, State of Montana, Year ending November 30th, 1890

. Journal Publishing Company, Helena.

Winchell, Alexander Newton

1914 "Mining Districts of the Dillon Quadrangle, Montana and Adjacent Areas",

U. S. Geological Survey, Bulletin 574

.

Work Projects Administration (WPA) Mineral Resources Survey

1941

Montana Mine Index

, An Alphabetical Index Arranged by Counties, Districts and Mines of Information on Montana Mines from 1867-1940. Montana School of Mines, Butte.