Sherman Mine


sherman on geo map

The Sherman Mine site, discovered in 1885, lies on the western slopes of Ready Pay Gulch east of Hillsboro, New Mexico, USA (see the detail from the Hillsboro Geologic Quadrangle and Google Earth view - both right).  The commodities taken from the Sherman site were Gold, Copper, and Silver - primarily in ores of  Chalcopyrite and Argentite.  The host rock at this site is Andesite.  The Sherman Mine is also known as the Sherman Group and/or the Caballero Group.  The Sherman Vein is one of several radial veins associated with the Copper Flat Monzonite Porphyry.  It was last mined in 1941 when it was owned by B. Caballero and operated by William Abbott, both of Hillsboro.  The deposits at the mine “occur in a vein of fractured andesite averaging 4 ft. in width and containing irregularly distributed small stringers of ore-bearing quartz”.

George Townsend Harley’s 1934 paper “New Mexico State Bureau of Mines and Mineral Resources, Bulletin 10, The Geology and Ore Deposits of Sierra County, New Mexico” - often simply called “Bulletin 10” is a seminal work on the geology and mining of this area.  At page 140 he notes that mining and/or development work was being done at the Sherman site during 1931-1933.  At page 156-7 he notes that “The Sherman vein or ‘lead’ as it is called locally is on the west sidehill above Ready Pay gulch and strikes slightly east of north. It has been opened by 400 feet or more of underground workings, which are now either caved or filled with water. Some stoping has been done on this vein, but the amount is not known.  The vein at the surface is a 4-foot fracture zone in andesite, through which small stringers of quartz are irregularly distributed. The dump from these workings is said to consist of 6,000 to 7,000 tons, over 50 per cent of which will pass a 10-mesh opening without further crushing. According to small-scale tests, these fines contain nearly all of the gold and assay $5 per ton. In 1932 this dump was under lease, and the operators were engaged in installing a second-hand Plat-table, upon which, they said, laboratory tests indicated that a concentrate worth $100 per ton in free gold and sulfides could be made.”

Ready Pay Gulch Mine Sites

In the 1957 Bulletin 39 of the State Bureau of Mines and Mineral Resources - “The Metal Resources of New Mexico and Their Economic Features Through 1954” Eugene Carter Anderson notes that (p. 124) “lode mines that operated at intervals during the period 1935-1938 were the... Portland-Sherman-Caballero...A small amount of ore from the Conner Boy-Bank and Sherman was treated in a mill at Hillsboro in 1937.”

D. C. Hedlund’s 1985 (preliminary) report “United States Department of the Interior Geologic Survey - Economic geology of some selected mines in the Hillsboro and San Lorenzo quadrangles, Grant and Sierra Counties, New Mexico” page 11 describes the Sherman Vein as - “The Sherman vein is west of Ready Pay Gulch and strikes N. 45U E.The vein is slightly mineralized over a distance of about 4,000 ft (1,200 m) and is about 2-4 ft (0.6-1.2 m) thick. Numerous small stringers of vein quartz follow thin fracture zones within the andesite; oxidized pyrite was the only ore mineral observed on the outcrop.”

In 1899 The Mining Reporter noted that “Jeff Owens, lessee of the Sherman Mine at Hillsboro, is making a 60 ton shipment to the Porter Mill.” (p. 129)

There is an open shaft, some filled shafts and surface workings at the site now.  Nearby are old ore trucks (see below). Photographs on this page were taken on May 31. 2016.

















© Robert Barnes 2018