Seven Troughs Mining District
The Seven Troughs Mining District is in the Seven Troughs Range.<ref name="Tingley1998">Joseph V. Tingley, "Mining Districts of Nevada," Report 47, Nevada Bureau of Mines and Geology, 1998, 2nd Edition. See map for details.</ref><ref>Frederick Leslie Ransome, "Notes on Some Mining Districts in Humboldt County, Nevada," USGS Bulletin 414, pp 14-25, 1919.</ref>
Stuart (1909) writes: "Seven Troughs, discovered in 1905, one of the most prominent mining districts has been the scene of marked activity for the past two years. The ledges here are well defined and traceable for long distances and justify the belief that development will place this district in the line of producers."
"One of the best properties is known as the Consolidated Development has exposed two feet of ore that will mill $35 per ton. The company has installed a compressor and is using machine drills in the driving of a tunnel which will cut the ore bodies at a depth of 600 feet. Considerable ore has been developed of a milling grade."
"The Florence lease owned by the Darby Consolidated has been opened up to a depth of 300 feet A drift is being run from the 300 foot level to cut the ore shoot which carries sensational values at the 200. A large quantity of ore is blocked out ready for stoping. The west vein is now being drifted upon and some fine shipping ore has been encountered The formation of this mine is igneous.
"The Mazuma Hills Leasing Company in its lower workings has exposed a large body of very rich ore It has been the object of the company to increase the equipment as the production justifies."
"The Seven Troughs Trio known as the Potter Arnett lease on Mazuma Hill has struck some very fine specimens of ruby silver in the developments now in progress.
"The Regan Syndicate in Wild Horse Canyon has a very attractive lease. In a drift from the 100 foot level two feet of ore were encountered of a high grade milling quality. On the foot wall of this property a stringer several inches in width shows values better than $100 per ton."
"The Wiwauja lease is at present being actively developed. Some very high grade shipping ore has been encountered in the workings."
"There are many other leases operating among which might be mentioned the Harris lease, the Van Winkle lease, and the Prior- Chatbourne lease.
"The Seven Troughs Company's Fairview mine is the most extensively developed mine in this district A nice showing of milling ore has been exposed The high grade ore in this property occurs in lenses which are continuous to their lowest depths The outlook for this property is very encouraging."<ref>E. E. Stuart, "Nevada's Mineral Resources," State Printing Office, Carson City, Nevada, p. 121-122, 1909.</ref>
Young (1918) writes: "The sixth plant Fig 5 is the mill of the Darby Reduction Co at Mazuma. It is probably the best attempt of those illustrated to provide an adequate plant for a small district. The mill was equipped with an automatic sampler of the Vezin type ten 1000 lb stamps, a 4 x 17 ft tube mill, Dorr classifier, amalgamating plates, four agitators and an Oliver filter. It contained practically all of the elements of a successful custom plant and was well designed and constructed. What its success has been and how well it has served the Seven Troughs and Mazuma district I am unable to say but details of its past history and present position would be interesting. Someone familiar with the enterprise should present it to readers of the Journal.<ref> G. J. Young, "Co-operation Among Small Mines," Engineering and Mining Journal, volume 106, p. 813, 1918. Includes photo of the Darby Mill at Mazuma.</ref>."
Lincoln (1923) states that the district was organized in 1905. In 1909, the Darby mill at Mazuma started operation and was dismantled in 1918<ref>Francis Church Lincoln, "Mining Districts and Mineral Resources of Nevada," Verdi, Nev.: Nevada Newsletter Publishing Co., p. 216, 1923.</ref>.
- "Nevada And The Southeastern Portion Of California," Third Edition, The Clason Map Company, Denver, Colorado, 1907. Map showing the Seven Troughs District and the town of Seven Troughs.
- Adams, W. S., "Cyanide Practice at the Darby, Nevada, Ore Reduction Co.," Mex. Min. Jour. 11 (1910) 75.
- Crehore, L. W., "Modern Cyanide Mill at Mazuma, Nevada," M&EW Sept. 11, 1909.
- J. M. Hill, "The mining districts of the western U.S.," U.S.G.S. Bull. 507, 1916.
- WeedMH. 1183 Delaware M. Co. 1308 Province Ex. Gold M. Co. 1326 Seven Troughs Reorg. Ms. Co.
- Hugh A. Shamberger, "The story of Seven Troughs, Pershing County, Nevada," USGS 1972.