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Gold Hill Mill DMO <br />September 2022 B-1 <br /> <br />Exhibit B Site Description <br />The Gold Hill Mill is a milling facility designed to treat gold-silver telluride mineralization <br />characteristic of the historical Gold Hill mining district, located within a mile of Gold Hill, CO. <br />Originally part of the Cash Mine permit, it was separated out into its own permit in 1994. It consists <br />of a mill area and a water pipeline area. Mill facilities such as the mill building and the tailings <br />storage facility have been in place and operating since the 1970s, with improvements in the 1980s <br />and 1990s. The mill facilities sit atop a ridge along the south side of Sunshine Canyon Road while <br />the water pipeline easement runs from the north side of Sunshine Canyon Road downhill, further <br />north, to Left Hand Creek. The water pipeline is accessible via Lick Skillet Road. The water <br />pipeline’s uphill end enters the Times-Wynona Mine via a portal on the north side of Sunshine <br />Canyon Drive. The Times-Wynona Mine extends beneath Sunshine Canyon Road and the mill <br />area. The Times-Wynona is connected to the mill via the Wynona Shaft and Times Drillhole. <br />The total permit and affected area is 9.20 (9.187) acres. All disturbance associated with the <br />operation has already taken place. No new disturbance is proposed as part of this 2022 110D <br />permit. <br />Map E-1 shows the permit area and ownership. Map E-2 shows the extent of operations. Map E-3 <br />details the reclamation plan. Map E-4 shows the Times-Wynona Mine. Map E-5 shows details of <br />the tailings storage facility. <br />1. Geology <br />The Gold Mill Hill sits atop a ridge immediately east of Gold Hill, CO at an elevation of 8400’ (Figure B- <br />1). Situated within the Colorado Mineral belt, the mill operation was historically fed from restored <br />underground workings in one of the historical mining operations in the immediate vicinity of the mill. <br />These hist orical mining operations produced gold and silver from narrow, high-grade gold-silver <br />telluride mineralized epithermal quartz veins hosted within the Precambrian Boulder Creek <br />Granodiorite. Mineralization is related to a serious of much younger, Tertiary shallow intrusives that <br />occur within this area, near the northern extremity of the Colorado Mineral Belt. The Gold Hill Mill is <br />located in the heart of the Gold Hill district of the Boulder County gold-silver telluride belt, a world-class <br />mineralized district of historical significance. <br />The Boulder County, Colorado telluride belt is located at the northeastern end of the Colorado Mineral <br />Belt and contains the Gold Hill, Central, Jamestown, Magnolia and Sugarloaf mining districts. The <br />telluride belt is part of a broad, north-trending area of mineralization encompassing about 50 square <br />miles. The predominant country rocks are Precambrian granites, gneisses and schists which are <br />bounded on the east by Paleozoic and Mesozoic sediments which form the foothills west of Boulder. <br />The Precambrian rocks have been intruded by Early Tertiary stocks and dikes that range in <br />composition from diorite to sodic granite. Gold -silver telluride mineralization is a product of <br />hydrothermal activity related to these Tertiary intrusives and is both temporally and spatially related to <br />them.