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<br />GOI~ flIIl PROJECT PAGE r-1 <br />4- HISTORY <br />Gold mining in Boulder County started in 1858, initially as placer <br />workings, neaz Gold Hill by the first Colorado settlers. In June 1859 <br />the Hosfal lode was discovered (2000 feet north east of the Cash Sha- <br />ft) and it became Gold Hills most productive mine. By 1860 the town <br />of Gold Hill had a population of 2,000 as new mines opened. By <br />1876, when Colorado became a State, the railroad had reached <br />Denver and Boulder became a University town. In 1873 two miners <br />i had a sample of purple coloured ore assayed and were informed that <br />' tellurium was present in combination with gold and silver. In 1873 a <br />new gold msh started. The Cash Mine opened in 1904. <br />The productive veins in the azea were followed to depths of between <br />300 and 600 feet deep with the exception of the Slide Mine (1,080 <br />feet deep) and the Ingram Mine (950 feet deep). In most mines the <br />veins did not pinch out at depth and were abandoned because of the <br />low gold price and water problems. By the First World Waz mining <br />was in decline. <br />During the depression in the 1930's small under financed operations <br />started. These were closed down by the Gold Mining Restraining <br />Order at the start of the Second World Waz. Table 1 shows the <br />annual production from 1904 to 1939. Figure 3 shows the location of <br />the ]mown veins and the o]d mines. <br />'I The grade of the Cash Mine ore was considered medium to high for <br />the azea, ragging from 0.65 to 5.85 ounces per ton of gold and 4S to <br />26 ounces of silver. <br />,I In 1958 Chazles A Steen, who had found and stazted the major <br />uranium mines in Utah in the late 1940'5, became interested in the <br />~ Gold Hill district and acquired the Cash, Rex and Victoria urines. <br />'' Between 1958 and 1964 a total of 19,000 tons of ore were delineated <br />at a cut-off grade of 1 ounce per ton gold. At that time the gold <br />1i price was 535 per ounce and Chazles Steen Beaded to wait for better <br />prices before attempting to reopen the mines. <br />~ Ig 1982 the Steen family formed Gold Hill Ventures to exploit the <br />'i ]mown reserves in the Cash Mine, acquire surrounding claims and to <br />. build a 50 ton a day gravity and flotation concentrator. The concentr- <br />ator was built in 1986/87 an in 1988 stockpiled development ore and <br />1j old dump material were processed. A total of 53S million was spent <br />on the mill, refurbishing the old Cash shaft and on a minor amount <br />'I of underground development. The operation was undercapitalized and <br />the old inclined shaft, which follows the Cash Vein, was a production <br />bottleneck. <br />1I <br />R. W. Tumer C.Eng. <br />Consulting Mining Engineer <br />