The Slate Creek district is located southwest of Darby in the Bitterroot Mountains in the southern end of Ravalli County. Slate Creek is a tributary of the Painted Rocks Lake which is at the head of the West Fork of the Bitterroot River. Despite its proximity to the long-lived placer grounds along Hughes Creek, Slate Creek had no known placer activity and no significant lode mines. Sahinen (1935) reports, "Production has been unimportant and none has been reported for many years."
The rocks underlying the Slate Creek district are granite porphyry of the Idaho batholith, which is covered at the southern end with Tertiary volcanics. Isolated ore deposits are found in veins. In the Slate Creek mine, the predominantly galena vein occurs in association with an aplite dike (Sahinen 1935; Sahinen et al. 1962).
BOUNDARIES OF THE DISTRICT
Sahinen (1935), the only one to discuss the district, describes it in relation to Slate Creek, noting that it "is a tributary of the South Fork of Bitterroot River, entering that stream from the east about 30 miles south of Darby...." Figure 1 shows the district as defined by the AMRB (1994) with a smaller area described around Slate Creek as defined by Sahinen (1935).
HISTORIES OF SELECTED MINES
The only mine mentioned in the literature is the Slate Creek mine, but there is no historical information given. Apparently the deposit is a relatively recent discovery, and operators were ascertaining transportation costs in 1962. At that time, consulting geologists did not consider the ore of commercial value (Sahinen et al. 1962).
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
Sahinen, Uuno Mathias
1935 "Mining Districts of Montana", Unpublished Master's thesis, Department of Geology, Montana School of Mines, Butte.
Sahinen, Uuno M., Francis M. Young, and Frank A. Crowley
1962 "Marketing Problems of Small Business Enterprises Engaged in Lead and Zinc Mining",
. Montana Bureau of Mines and Geology, Butte.