aka Yahk, Yakt, Yaak, Yaak River

The Sylvanite mining district encompasses a large section of rugged and remote land north and west of the bend in the Kootenai River in northwestern Montana. The most important placer and lode mining activity concentrated along the Yaak River valley, especially near the town of Sylvanite. In addition, the Rainy Creek sub-district became well-known for its deposits of vermiculite.

Protozoic rocks of the Belt series underlie the Sylvanite district. Ore deposits are related to the geological structure, i.e., faulting and folding. Gold-quartz veins, such as those located in the Sylvanite district, are found in the Prichard Formation where they "parallel bedding planes, and most ore is produced near high-angle crosscutting faults." The lead which runs through the Keystone and Goldflint mines is found in quartzite between two folded beds (Johns 1970; Sahinen 1935).

The first prospectors in the rugged Sylvanite district came as a result of strikes elsewhere in the region. Bill Hall claimed to have found the first placer gold in the Yaak River in 1864 when he stopped briefly to pan for colors while on his way north to the Kootenay rush in British Columbia. More than twenty years later, after the placers on Libby Creek were developed, prospectors fanned out to look for new discoveries. Some found gold along the lower reaches of the Yaak River in the late 1880s and established a temporary camp known as Snipetown around 1890. The number of miners grew three years later with the discovery of placer gold just over the border on the Moyie River in Idaho, and many miners from the new camp came to try their luck in the Yaak. The proximity of the Idaho border confused quite a few miners who recorded their claims in Idaho (Calvi 1993; Renk 1994).

While placer mining concentrated along the Yaak River in the vicinity of Snipetown, a few other areas of the district were tested and worked. There are unverified reports of placer mining along China Creek and near China Lake during the late nineteenth century. Solo Joe Perriault worked his claim (24LN90) along the East Fork of the Yaak River in the early 1900s, followed by a Captain Mappot from about 1938-1940; total production was small. An unknown individual worked the Copeland placer during the 1930s. The mine included a cabin, a 75-foot flume, and a water wheel. There are no production figures for the placer, but the total was probably small. The Snipetown placer also revived during the mid-1930s when R. Moore, J. Lewis, M. D. Powely, and Mr. Packingham leased the ground about 3.5 miles below Yaak Falls. They built a flume to wash gravels through sluice boxes, bringing in $.90 to $3 per cubic yard during 1934 - 1935 (Johns 1970; Hauge 1994).

While the placer finds never attracted much attention, the discovery of a quartz lode with free gold brought a small rush. Pete Berg and Bill Lemley made the find on Crawford Creek in 1894, and within a year 100 men were working on claims (Timmons 1986; Renk 1994).

William Johnson and S. J. Whitcomb located the Keystone mine, one of the most important claims in the district, in 1895, and before the end of the year they had bonded it to a group of Spokane capitalists for $12,500. Charles H. Bartlett and E. J. Merrin located the Goldflint mine the same year, and it soon joined the Keystone in importance. Development proceeded on both prospects over the next three years. Forty-eight men worked at the Keystone in 1896 when the plant facilities included a water-powered 10-stamp mill, office, ore bins, and bunkhouses (Timmons 1986; Byrne and Hunter 1899).

The town of Sylvanite grew with the mines. Originally called Lemleyberg, the camp soon changed its name to acknowledge the type of ore that miners believed they had found. Developers platted streets and lots in 1896, and by the next year the town had two hotels, two restaurants, three stores, a meat market, post office, brewery, and the requisite saloons. A sawmill turned out lumber for mine and town buildings. At its peak, Sylvanite was home to 500 people (Timmons 1986; Renk 1994).

The boom soon turned to bust. The year 1898 started off well with the completion of the new 20-stamp Goldflint mill. The Keystone mill ran steadily, processing 30 tons of ore each day. By August, however, the town was nearly deserted and both the Goldflint and Keystone mills were silent. MacDonald (1909) hypothesized that the mines closed when the ore at depth became base so that it could no longer be processed as free milling ore (Byrne and Hunter 1899; Timmons 1986; MacDonald 1909).

After more than a decade of inactivity, Canadian investors formed the Lincoln Gold Mining Co. in 1910 to operate the Keystone and Goldflint. They reopened the mines, constructed a 20-stamp mill and tramway, and infused new life into the district. Before the mill ever operated, however, a forest fire swept through the valley in August and burned the mill and mine structures along with all but one building in town. Although the company planned to rebuild, it never did. The mines revived in the 1930s under different ownership, operating from 1931-1937 (Timmons 1986; Renk 1994).

Rainy Creek Sub-district

The Rainy Creek sub-district encompasses a small area northeast of Libby in the Rainy Creek drainage. Prospectors located isolated copper deposits there in the late 1890s and early 1900s. John L. Neihart, of the mining town of Neihart, caused considerable excitement when he examined these deposits and predicted that they would make the Rainy Creek district "another Butte in the production of copper" (Renk 1994).

Copper mining never developed much beyond the stage of wishful thinking, but the Rainy Creek district became well-known for a very unassuming mineral called vermiculite. Mica particles heated expands up to 15 times their original size. The end product is vermiculite, which is used primarily in fireproofing and insulation from heat, cold, and sound (Renk 1994; Perry 1948).

Large deposits of vermiculite and small metallic deposits in the Rainy Creek sub-district are found in a stock of alkaline rocks that intrudes into the Proterozoic rocks of the Belt series. Two-thirds of the stock is coarse-grained pyroxenite, from which vermiculite is derived, and one-third is coarse-grained syenite. Hydrothermal alteration has caused major changes in the stock, producing white mica, aegirite and aegirite-diopside, vermiculite, and fibrous amphiboles (Pardee and Larsen 1929).

Edward N. Alley discovered the vermiculite deposits during World War I when he was prospecting for vanadium. He experimented with samples, built a small kiln to process the ore, and promoted the material under the trade name of Zonolite. This led to a demonstration plant in 1924, followed two years later by a larger facility capable of processing 100 tons of ore each day. Alley sold his interests in 1934, leaving two different companies working the deposits on Rainy Creek. They merged in 1939 to form Universal Zonolite Insulation Co., altering the name to the Zonolite Co. in 1948. The business came under the control of W. R. Grace and Co. in 1963 and continued operations until 1991 (Renk 1994).

Operators mined most of the vermiculite ore through large open cuts; several adits, one 750 feet long, also provided access to the ore. Initial processing took place at a concentrator near the mine. Trucks then hauled the concentrate to the Libby plant for heating and expansion into the final product. Some of the concentrates were shipped to plants in Great Falls, other states, Canada, and other foreign countries for final processing there. About 1940, Universal Zonolite mined 500 tons of ore each day, reducing it to 200 tons of concentrates. Twenty-four years later, the company turned out 2400 tons of ore each day, reducing this amount to 500 tons of concentrates. There are no figures for total production since this information was restricted after 1930 (Perry 1948; Johns 1970; WPA 1941).


Sahinen (1935), the only one to describe the Sylvanite district, places it on the Yaak River, about 10 miles northwest of Troy. He describes the Rainy Creek sub-district as about seven miles northeast of Libby in the Rainy Creek drainage (Figure 1).


Black Diamond

The three unpatented claims of the Black Diamond mine are located 1.5 miles west of Teepee Mountain. After its discovery in the early 1920s, Charles Cone and others formed the Black Diamond Mining Syndicate to develop the mine. Most activity occurred during the 1930s when the company erected a 100-ton gravity flotation mill that produced a lead-zinc concentrate containing 30 percent lead. The company spent $30,000 on improvements which, besides the mill, included a sawmill, bunkhouse, and powerhouse. The Black Diamond reported production in 1922 and 1930 and warranted mention in other mining literature in 1936 and 1938-1940. It was idle by 1941 (Johns 1970; Gibson 1948; WPA 1941).

Morning Glory (Keystone and Goldflint)

The property later known as the Morning Glory encompasses the Morning Glory claim, as well as the important Keystone and Goldflint claims. They are located near the historic town of Sylvanite on the Yaak River.

Both the Keystone and Goldflint claims were located in 1895, the former by William Johnson and S. J. Whitcomb and the latter by Charles H. Bartlett and E. J. Merrin. Within a short time, Johnson and Whitcomb bonded the Keystone to a group of Spokane capitalists for $12,500. Development work proceeded rapidly, and within a year the mine included a 10-stamp mill, office, ore bins, and bunkhouses. During one especially good run in 1897, the Keystone mill recovered $1900 of gold from 308 tons of ore. Work on the Goldflint went well also, with three shifts of men working in a 450 foot tunnel in 1897. Crews had a 20-stamp mill operating there by January of the next year (Timmons 1986; Byrne and Hunter 1899).

Although the initial returns from the mines looked promising, the boom turned to bust. By August 1898, the mines and mills were closed and the town of Sylvanite was nearly deserted. MacDonald (1909) suggested that the ore may have turned base as the mines deepened, rendering the mills ineffective. The Keystone and Goldflint mines were consolidated in 1899, the same year that the Keystone was patented; the Goldflint was patented five years later (Timmons 1986).

After a decade of quiet, Sylvanite came to life again in 1910. Canadian capitalists paid $75,000 for the Keystone and Goldflint claims and formed the Lincoln Gold Mining Co. to run the mines. A 2400-foot tramway carried ore from the Keystone mine, and the mills began processing ore. Both soon shut down as the company started a major renovation project that included a new 20-stamp mill. The first batch of ore had yet to be processed when disaster struck the Sylvanite district. A forest fire on August 26 left just one building in town standing and leveled everything at the mines. Lincoln Gold Mining Co. placed the loss at $40,000, while damage in the town totaled $75,000. The company announced plans to rebuild and even ordered lumber in 1911, but this reconstruction never occurred (Timmons 1986; Walsh and Orem 1910; 1912).

The Keystone and Goldflint came to life one more time, making a very profitable run during the 1930s. Percy Goodwin and Frank McNees leased the properties, and they and a small crew began operations in August 1932. Within a short time, the mill was processing 40 tons of ore every 24 hours, running continuously. Three hundred tons of especially good ore yielded $4000 in gold in August 1937. The total production from 1931-1937 amounted to 22,200 tons of ore worth $246,000. Work continued intermittently on the mines, and in 1939, a crew of 18 men were driving a 1,500 foot crosscut (WPA 1940; Timmons 1986; Johns 1970).

Joe Thornton, a partner with Goodwin and McNees, formed the Haywire Mining and Milling Co. in 1936. The new corporation acquired a number of claims near Sylvanite and constructed a 10-stamp mill (24LN263) around 1937 on the west side of the Yaak River road. The mill processed ore from the Keystone and Goldflint mines, running until around 1942. Morning Glory Mines, Inc., owner of the Keystone and Goldflint, bought the Haywire Co. in 1946, further consolidating the claims at Sylvanite. They converted the stamp mill to a ball mill and ran from 1946 to around 1951. Morning Glory Mines declared bankruptcy in 1952. The last activity on the Keystone group occurred in the late 1950s (Friedman et al. 1983; Johns 1970).


The Victoria mine is located near the Keystone. Owner Fred Lang worked the property from 1910-1912 when an 800-foot tunnel provided access to the copper-gold-silver ore. Although Lang made several shipments of ore, there are no production totals for the mine (Johns 1970; Walsh and Orem 1910; 1912).


Byrne, John, and Frank Hunter

1899 10th Annual Report of the Inspector of Mines of the State of Montana for the Year Ending Nov. 30, 1898.

Calvi, Jim

1993 Trails & Roads to Sylvanite and the Yahk Mining District, 1864-1897", Report prepared for the Three Rivers Ranger District, Kootenai National Forest.

Friedman, Paul, D., James M. Brechtel, Marilyn A. Martorano, and Deward E. Walker, Jr.

1982 "Final Report of Cultural Resource Investigations Along Montana Forest Highway #62, Yaak, Montana", Powers Elevation / Archaeology Department. Submitted to National Park Service, Contract No. CX-1200-2-B022.

Gibson, Russell

1948 "Geology and Ore Deposits of the Libby Quadrangle, Montana", U.S.G.S. Bulletin 956. Government Printing Office, Washington, D. C.

Hauge, Kristen

1994 "A Cultural Resource Inventory of the Robert Copeland Timber Sale", Kootenai National Forest.

Johns, Willis M.

1970 "Geology and Mineral Deposits of Lincoln and Flathead Counties, Montana", Bulletin 79. Montana College of Mineral Science and Technology, Butte.

MacDonald, D. F.

1909 "Notes on the Economic Geology", In A Geological Reconnaissance in Northern Idaho and Northwestern Montana, by F. C. Calkins. U.S.G.S. Bulletin 384. Government Printing Office, Washington, D. C.

Pardee, J. T., and E. S. Larsen

1929 "Deposits of Vermiculite and Other Minerals in the Rainy Creek District, Near Libby, Mont.", In Contributions to Economic Geology. Part I. Metals and Nonmetals Except Fuels. U.S.G.S. Bulletin 805. Government Printing Office, Washington, D.C.

Perry, Eugene S.

1948 "Talc, Graphite, Vermiculite and Asbestos Deposits in Montana", Memoir No. 27. Montana School of Mines, Butte.

Renk, Nancy F.

1994 "Mining", In Historic Overview of the Kootenai National Forest, Vol. 1, edited by Christian J. Miss. Northwest Archaeological Associates, Inc., Seattle.

Sahinen, Uuno Mathias

1935 "Mining Districts of Montana", Unpublished Master's thesis, Department of Geology, Montana School of Mines, Butte.

Timmons, Rebecca S.

1986 "A Culture History of the Yahk Mining District", Unpublished Master's thesis, University of Montana, Missoula.

Walsh, William, and William Orem

1910 Biennial Report of the Inspector of Mines of the State of Montana For the Years 1909-10. 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.

1941 Montana Mine Index, and Alphabetical Index Arranged by Counties, Districts and Mines of Information on Montana Mines from 1867-1940. Montana School of Mines, Butte.