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Page 1 <br /> Technical Memorandum <br /> DATE: 7 May,2020 PROJECT: Cross Mine <br /> ATTENTION: Richard Mittasch COMPANY: Grand Island Resources,LLC <br /> PREPARED BY: Dave Hallman,PE,PG REVIEWED BY: RM <br /> SUBJECT: Idaho Tunnel Portal—Slope Stability Analysis <br /> 1.0 INTRODUCTION <br /> This Technical Memorandum has been prepared to present geotechnical stability analyses for the slopes <br /> adjacent to the Idaho Tunnel Portal in response to a Minerals Program Inspection Report from DRMS <br /> dated March 26, 2020 in conjunction with the Cross Mine, DRMS Permit No. M-1977-410. As indicated <br /> in the Inspection Report from DRMS, the Idaho Tunnel (at the Caribou Mine) has collapsed creating <br /> potential slope stability issues near the northern permit boundary and the adjacent Caribou Road. This is <br /> a concern pursuant to Rule 3.1.5(3)and C.R.S.34-32-116(7)(h)which require areas outside of the affected <br /> land to be protected from slides or damage occurring during the mining operation and reclamation. <br /> The stability evaluation presented was based largely on observation and professional judgement as <br /> limited engineering data was available. This work was conducted by Mr. David Hallman, a geological <br /> engineer with 37 years of experience and licensed as Colorado Professional Engineer (Civil) 26076, as <br /> affirmed by the stamp and signature affixed at the end of this document. <br /> 1.1 BACKGROUND <br /> 1.1.1. Location <br /> The Cross Mine site is located approximately 3 miles west of Nederland, Colorado adjacent to the <br /> Roosevelt National Forest,at an elevation of 9700 feet above mean sea level (MSL).The general location <br /> is parcels of land in Section 9,Township 1 South, Range 73 West of the 6 Principal Meridian, County of <br /> Boulder, State of Colorado. This is an existing hard rock mining operation owned by Grand Island <br /> Resources Inc. (GIR),although at present,no active mining is being conducted. <br /> 1.1.2. Portal Rehabilitation <br /> Entrance to the Idaho Tunnel at the mine site was in such a state of neglect and disrepair from long-term <br /> gradual deterioration that it was not safe to enter and operate the mine water system per the approved <br /> permit. In particular, the timber ground supports at the portal were tilted dangerously askew and the <br /> ground slopes adjacent to the portal also exhibited signs of shallow slope failures and sloughing, such as <br /> titled trees(Photograph 1). <br /> Applied GeoLogic LLC 5/7/2020 <br />