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Applied GeoLogic LLC 5/7/2020 <br />Technical Memorandum <br />DATE: 7 May, 2020 <br />ATTENTION: Richard Mittasch <br />PREPARED BY: Dave Hallman, PE, PG <br />PROJECT: Cross Mine <br />COMPANY: Grand Island Resources, LLC <br />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 />Page 1