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TRAUTNER-IST I) ;to e <br /> ANC ENO.NEERING GEOLOG <br /> October 11, 2019 <br /> Mr. Eli Doose <br /> Atlas Mining and Reclamation Company LLC <br /> 19911 Hwy 550 <br /> Montrose, Colorado 81403 <br /> c/o Mr. Mike Thompson, Reardon Steel, LLC; mt@reardonsteel.us <br /> PN: 55743PE <br /> Subject: Von Doose Mine <br /> Slope Stability Overview <br /> Ouray County, Colorado <br /> Mr. Doose, <br /> This letter presents our comments based on our July 16,2019 site observations and meeting. As <br /> requested,we are providing a brief geotechnical engineering commentary and overview of your <br /> proposed waste rock dump. At the time of our July 16, 2019 site observations and meeting we <br /> discussed our limitations and inability to access the proposed tailing site with our track mounted <br /> drilling equipment for subsurface exploration. We understand that based on our August 5, 2019 <br /> telephone conversation with Mr. Mike Thompson that officials from the Colorado Division of <br /> Mining Reclamation and Safety met with you at the proposed mine site and stated that <br /> subsurface exploration is not required as part of the current slope stability comments. The <br /> information below is based on our experience with similar projects, our literature research and <br /> our surface observations conducted at the site. <br /> The proposed mine operation is situated on the northeast flank of Red Mountain No. 2. The <br /> slope gradient within the proposed portal and adjacent waste rock dump are about one and one- <br /> half to one (11/2:1,horizontal to vertical)and locally steeper. The slope inclinations within the <br /> lay-down yard area are slightly flatter. <br /> We observed the thin soil and formational material ("bedrock")that were exposed along the <br /> access roadway cuts. The soil mantle exposed within most of the cuts was very thin to non- <br /> existent. We suspect that the thickness of the soil is deeper in the areas closer to County Road <br /> 20A due to colluvial transport to deposition along the lower elevations at the site. <br /> The Tertiary Henson formation is shown as the dominant geologic unit underlying this site. <br /> The Henson formation is primarily Rhyodacite and Rhyolite within this area(From: 1964, <br /> Burbank, WS, and Luedke, RG, Geology of the Ironton Quadrangle,: U.S. Geological Survey, <br /> Geologic Quadrangle Map, GQ-291, scale 1:24,000). The unit is competent,but highly fractured <br /> where exposed near the ground surface or in excavation cuts. <br /> It is our understanding that the proposed operation will include blasting with deposition of <br /> waste rock on the slope below the proposed portal location. The working face of the waste rock <br /> 649 TECH CENTER DR DURANGO, C0 95 N HENRY ST, CORTEZ, CD <br /> 970-259-5095 970-529-2020 <br />