MINERA PLATA REAL, S. DE R.L. DE CV JOINT VENTURE OF SUNSHINE SILVER MINING & REFINING CORPORATION (51.5%) AND DOWA METALS & MINING CO., LTD. (48.5%) VALLE ESCONDIDO NO. 5500 COMPLEJO INDUSTRIAL EL SAUCITO PUNTO ALTO E-2, SUITE 404 CP, 31125 CHIHUAHUA, MEXICO Los Gatos Project Chihuahua, Mexico Project No.: 117-8302008 Effective Date: July 1, 2020 Issue Date: July 2020 Prepared by: Guillermo Dante Ramírez-Rodríguez, PhD, MMSAQP Leonel Lopez, SME-QP Kira Johnson, MMSAQP Keith Thompson, C.P.G. Kenneth Smith, SME-QP Luis Quirindongo, SME-QP Max Johnson, P.E. 350 Indiana Street, Suite 500 | Golden, CO 80401 303.217.5700 | tetratech.com Los Gatos Project Chihuahua, Mexico TABLE OF CONTENTS 1.0 SUMMARY ................................................................................................................................... 1 1.1 Introduction ..................................................................................................................................... 1 Property Description, Location and Infrastructure ...............................................................................1 1.2 History .............................................................................................................................................. 2 1.3 Geology and Mineralization ............................................................................................................. 3 1.4 Drilling .............................................................................................................................................. 3 1.5 Mineral Resource Estimates ............................................................................................................ 4 1.6 Mineable Reserve Estimate ............................................................................................................. 6 1.7 Metallurgical Testing ........................................................................................................................ 7 1.8 Mining Methods ............................................................................................................................... 8 1.9 Recovery Methods ........................................................................................................................... 8 1.10 Infrastructure ............................................................................................................................... 11 1.11 Marketing Studies and Contracts ................................................................................................ 11 1.12 Environmental Studies, Permitting, and Social or Community Impact ....................................... 12 1.13 Capital and Operating Costs ........................................................................................................ 14 LOM Capital Costs ............................................................................................................................ 14 LOM Operating Costs ....................................................................................................................... 14 1.14 Economic Analysis ........................................................................................................................ 15 1.15 Conclusions and Recommendations ............................................................................................ 16 Geology and Resources .................................................................................................................... 16 Mineral Reserves .............................................................................................................................. 17 Mine Planning .................................................................................................................................. 17 Mineral Processing and Metallurgy ................................................................................................. 18 Economics ........................................................................................................................................ 18 2.0 INTRODUCTION .......................................................................................................................... 19 2.1 Terms of Reference ........................................................................................................................ 19 2.2 Scope of Work ................................................................................................................................ 19 2.3 Units of Measure............................................................................................................................ 19 2.4 Detailed Personal Inspections........................................................................................................ 19 3.0 RELIANCE ON OTHER EXPERTS .................................................................................................... 20 4.0 PROPERTY DESCRIPTION AND LOCATION .................................................................................... 21 4.1 Location .......................................................................................................................................... 22 Mining Concession ............................................................................................................................. 22 Los Gatos and Paula Adorada Concessions ....................................................................................... 24 Internal Concessions not held by MPR ............................................................................................... 25 4.2 Surface Rights................................................................................................................................. 26 4.3 Environmental Permitting .............................................................................................................. 27 4.4 Environmental Liabilities ................................................................................................................ 28 TETRA TECH July 2020 i Los Gatos Project Chihuahua, Mexico 5.0 ACCESSIBILITY, CLIMATE, LOCAL RESOURCES, INFRASTRUCTURE AND PHYSIOGRAPHY ................. 29 5.1 Accessibility .................................................................................................................................... 29 5.2 Climate, Vegetation, Soils, and Land Use ...................................................................................... 29 5.3 Personnel ....................................................................................................................................... 30 5.4 Infrastructure ................................................................................................................................. 30 5.5 Population Centers ........................................................................................................................ 30 6.0 HISTORY ..................................................................................................................................... 31 6.1 Historic Resource Estimates........................................................................................................... 31 7.0 GEOLOGICAL SETTING AND MINERALIZATION ............................................................................. 32 7.1 Regional Geological Setting ........................................................................................................... 32 7.2 Property Geological Setting ........................................................................................................... 35 7.3 Mineralized Zones .......................................................................................................................... 37 8.0 DEPOSIT TYPES ........................................................................................................................... 41 9.0 EXPLORATION ............................................................................................................................ 44 9.1 Historic Exploration ........................................................................................................................ 44 9.2 Recent Exploration ......................................................................................................................... 44 9.3 Decline and Bulk Sample ................................................................................................................ 46 10.0 DRILLING .................................................................................................................................. 50 11.0 SAMPLE PREPARATION, ANALYSES AND SECURITY .................................................................... 53 11.1 Sample Preparation ..................................................................................................................... 53 11.2 Security ........................................................................................................................................ 54 11.3 Analyses ....................................................................................................................................... 54 11.4 Quality Assurance and Quality Control for Sample Analysis ....................................................... 56 Quality Control Sample Performance .............................................................................................. 56 12.0 DATA