aka Chief Cliff, Dayton Creek
The Elmo mining district (also known as Dayton Creek and Chief Cliff) is located in Lake County near the northern boundary of the Flathead Indian Reservation. It is within the Flathead Range north of the town of Elmo and in the vicinity of Proctor in the Dayton Creek drainage. Although many claims were staked as soon as the reservation opened for settlement in 1910, the mines in the district produced very little ore.
Lake Mary Ronan lies behind a moraine deposited by the Flathead Valley glacier. Overflow from the much larger ice-age version of the lake poured south along the edge of the glacier, eroding a deep channel in the bedrock. Chief Cliff was eroded as a bluff above the meltwater stream, and the dry channel still winds along its base. When the ice age receded, a moraine at the foot of Flathead Lake was left. Water filled the valley north of the moraine and drained through Wild Horse Bay and Big Draw westward to the Little Bitterroot River. A rise in the level of the lake resulted in the water overflowing the moraine, a lower lake level, a new (the present) outlet, and the uncovering of the Big Draw (Biggar 1951; Alt and Hyndman 1986).
Most of the valley floors in Lake County are occupied by glacial lake deposits and glacial drift. The predominant rock types in the mountains are quartzites, argillites, limestones, and dolomites of the Precambrian Belt Series. There is a marked absence of exposures of igneous rocks within the county, resulting in very few metallic lode deposits in the area and unimportant metal mining in the county (State Engineer's Office 1963).
As soon as the reservation was opened in 1910, hundreds of claims were staked; prospectors had already examined the area. In the following years many reports were made of rich strikes of gold, silver, copper, asbestos, and even oil, but real development took place only in the Hog Heaven district to the north. Between 1915 and 1918 three rich mines of copper and gold (assaying from $42 to $160 per ton) were being worked in the Big Arm and Dayton areas (Biggar 1951).
The two most significant mines in the district were the Chief Cliff and the Silverstone, both lead-silver mines. Neither one was a significant producer of ore. The Elmo Placer mine yielded gold (Sandvig 1947; State Engineer's Office 1963).
BOUNDARIES OF THE DISTRICT
In approximately 1909 the Kalispell Chamber of Commerce, in a promotional brochure, mentioned mines located "South of Kalispell, in the Dayton Creek district, and near Flathead Lake." Sandvig (1947) referred to the Silverstone, Chief Cliff, and Elmo Placer mines as being located in the Elmo district. Figure 1 shows the Elmo district as defined by AMRB (1994) as being a square mile north of Elmo. Other claims north in the Dayton Creek drainage are also included in a larger boundary.
HISTORIES OF SELECTED MINES
The Ballarot mine, located near Elmo, reported rich prospects in 1911 (Biggar 1951).
The Big Four prospect is located in Section 31, T26N R21W, on the North Fork of Dayton Creek. The claim was located before 1910 by a man named Wilhelm. Vein material consisted of white vuggy quartz and iron oxides. The workings were in quartzite and argillite of the Ravalli Group (Johns 1964).
The Chief Cliff mine had values in silver and lead (Sandvig 1947).
The Jumbo mine is in Section 6, T25N R21W, on a tributary of the North Fork of Dayton Creek. In 1901 the mine was owned by Sam Hilburn of Kalispell; considerable development work had been done at that time. Oxidized copper ore from the mine contained 6-25 percent copper. After being inactive for several years, the property was reopened in 1925-26. In 1930 a shot on the side of the old 900-foot tunnel exposed a vein of rich silver-lead ore that assayed from $58-217 per ton (
1930; Johns 1964).
A sample of vuggy quartz in the mine tailings contained 10.2 percent lead; 1.4 ounces silver; and 0.003 ounce gold per ton. The mine is located on Ravalli sedimentary rocks. About 1/4 mile west of the Jumbo adit, possibly on the apex of the Jumbo vein, is a quartz vein that was developed by a shaft, a trench, and two shallow pits (Johns 1964).
The Mosher prospect was located in approximately 1910 by Joe Mosher, who was grubstaked by Clarence E. Proctor. $40,000 was reportedly spent developing the prospect. The mine is located in Section 21, T25N R21W within two miles of the town of Proctor. Development included a shaft and an adit. The shaft and tunnel are in argillaceous quartzite and argillite of the Ravalli Group (Johns 1964).
The Rocky Gulch mine, located near Elmo, reported rich prospects in 1911 (Biggar 1951).
The Silverstone mine had values in silver and lead (Sandvig 1947).
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
Alt, David, and Donald W. Hyndman
Roadside Geology of Montana
. Missoula: Mountain Press Publishing Company.
Biggar, Hugh J.
1951 "The Development of the Lower Flathead Valley." M. A. thesis, Montana State University.
1930 "Report Rich Ore Strike In Jumbo Mine." February 20, p. 1.
Johns, W. M.
1964 "Geologic Investigations in the Kootenai-Flathead Area, Northwest Montana, No. 6, Southeastern Flathead County and Northern Lake County." Montana Bureau of Mines and Geology, Bull. 42.
1901 "Flathead Mining Industry" December 18, p. 13.
Sandvig, Robert L.
1947 "General Geology and Mines of Northwestern Montana." B. S. thesis, Montana School of Mines.
State Engineer's Office
Water Resources Survey, Lake County, Montana