The Eight Mile district, located east of Florence on the western slopes of the Sapphire Mountain range in the northeastern part of Ravalli County, contained a few minor lode mines and a small amount of placering.
The geology of the district is probably similar to that of the neighboring Three Mile district to the south. Sedimentary rocks of the Grinnell and Appekunny formations of the Belt series underlie the eastern portion of the district in the Sapphire Mountains. Farther west the underlying rock is granite from the intrusive Idaho batholith. Finally, Tertiary lake beds, Pleistocene silts from glacial Lake Missoula, and Recent alluvium cover the Bitterroot River valley and the lower reaches of its tributaries. Mineral deposits occur along the line of contact between porphyry and intrusive granite (Sahinen 1935; 1957; Lyden 1948).
Placering in the Eight Mile district was insignificant with the only reported production in 1934 when one operation recovered 4.15 ounces of gold, worth $145 (Lyden 1948; Sahinen 1957).
Prospectors discovered the White Cloud lode mine in 1866, but little was done on the claim until the 1890s. At that time, operators sank two shafts, and pushed a tunnel and crosscut to provide access to the ore vein. A 75-ton concentrator was running by 1897, but poor results caused the operators to close the mine the following year. It remained idled, with the exception of a brief test operation in 1938 (Byrne and Hunter 1897; 1898; Rowe 1911; Sahinen 1957).
There were other lode prospects in the area, but none attained any importance. In the early 1890s, George Swallow reported that the L. R. claim had run a tunnel in 100 feet but had not yet struck the ledge. In the same area, work in the Annie Bell mine had exposed a large body of free-milling gold ore in an 80 foot shaft. The Providence mine shipped ore to the East Helena smelter in 1907; the mine workings included a 100 foot inclined shaft. Montana Mines Co. worked on an 800 foot tunnel on the Gold Bug claim in 1912. Nothing more is written about any of these mines, suggesting that they were not profitable prospects (Walsh and Orem 1912; Sahinen 1957).
During the Depression, unnamed lode mines, possibly the White Cloud, produced small amounts of ore. In 1932, ore from one mine was valued at $627, with most of the value in gold. A mine the next year produced $99 worth of ore. In 1935, 13 tons of ore from one mine yielded 8 ounces of gold, netting the operators $280. The White Cloud shipped a test lot of ore in 1938, while the following year a mine produced 21 tons of ore, containing three ounces each of gold and silver, worth a total of $107 (Sahinen 1957).
Two other mines mentioned in the literature are probably the same, since both include the Red Rock claim and six associated unpatented claims. The first mentioned gold lode is seven miles east of Florence, putting it in the Eight Mile district. Montana Red Rock Mines, Inc. employed three men there around 1939 on development work. The tunnel at that time extended 800 feet. The second lode mentioned is five miles southeast of Florence, placing it within the Three Mile district. In 1949, this mine was idled, owned by the Anna Bell Mining and Milling Co. The underground workings included a 700 foot tunnel and 400 foot winze. Three men normally worked in the mine, and the owners planned to reopen (Lyden 1948; WPA 1940; Trauerman and Reyner 1950).
BOUNDARIES OF THE DISTRICT
George Swallow described the Eight Mile district in 1894, saying that it was "on the east side of the Bitter Root Valley, 16 miles from Missoula" (Sahinen 1957). The AMRB (1994) defined the district essentially as the Eight Mile Creek drainage (Figure 1).
HISTORIES OF SELECTED MINES
The White Cloud mine, located eight miles east of Florence along Eightmile Creek, was discovered in 1866. Marcus Daly may have been involved in the early development of the prospect. Work had progressed by 1894 when the mine contained two shafts 35 and 125 feet deep, a 225 foot tunnel, and a 47 foot crosscut (Rowe 1911; Sahinen 1957).
Later operators considered some of this early work inadequate, a threat to both miners' safety and the condition of the mine. John McCooey, the mine superintendent in 1897, had improved conditions considerably by then. The mine employed a crew of 12, with eight in the mine and four more on the surface. The main shaft had reached 140 feet, and the hoist utilized a 30 horsepower Ledgerwood engine, steel rope, and bucket. The iron pyrite ore containing gold was processed in a 75-ton concentrator at the mine. In 1898, however, operators Clark and Wheeler had an unsuccessful year and abandoned the mine. Rowe (1911) suggested that the problems may have come from using the wrong method of concentration, since gold-bearing pyrite ores require the tailings to be treated with cyanide. Despite Rowe's encouraging assessment of the property, the mine operated only briefly in 1938, shipping a small test lot of gold ore worth $57 (Byrne and Hunter 1897, 1898; Rowe 1911; Sahinen 1957).
When he examined the mine in 1911, Rowe tested samples of ore and found that assays ran from $2.50 to $50 in gold per ton, with small amounts of silver. There are no production totals for the mine (Rowe 1911).
Abandoned Mine Reclamation Bureau (AMRB)
1994 Mining districts of Montana. Maps 1:100,000 and Map #94-NRIS-129. Compiled and edited by Joel Chavez. Prepared by Montana State Library Natural Resource Information System (NRIS) for Montana Department of State Lands. Helena
Byrne, John, and Frank Hunter
1897 9th Annual Report of the Inspector of Mines of the State of Montana.
1898 10th Annual Report of the Inspector of Mines of the State of Montana.
Lyden, Charles J.
1948 The Gold Placers of Montana", Memoir No. 26. Montana Bureau of Mines and Geology, Butte, Montana.
1981 "Cultural Resources Inventory: Burlington Northern Land Exchange" Bitterroot National Forest Report No. 81-BR-1-4.
Rowe, J. P.
1911 "Gold Quartz Mining in Western Montana",
34 (May 20):1034.
Sahinen, Uuno Mathias
1935 "Mining Districts of Montana", Unpublished Master's thesis, Department of Geology, Montana School of Mines, Butte.
1957 "Mines and Mineral Deposits, Missoula and Ravalli Counties, Montana", Bulletin No. 8. Montana Bureau of Mines and Geology. Montana School of Mines, Butte.
Trauerman, Carl J., and Millard L. Reyner
1950 "Directory of Montana Mining Properties, 1949",
Memoir No. 31
. Montana School of Mines, Butte.
Walsh, William, and William Orem
1912 Biennial Report of the Inspector of Mines of the State of Montana For the Years 1911-12.
Work Projects Administration (WPA), Mineral Resources Survey
1940 "Directory of Montana Mining Properties",.
Memoir No. 20
. Montana School of Mines, Butte.