REPORT ON THE RESERVE ESTIMATE & FEASIBILITY STUDY FOR THE ISABELLA PEARL PROJECT, NEVADA REPORT ON THE ESTIMATE OF RESERVES and the FEASIBILITY STUDY for the ISABELLA PEARL PROJECT MINERAL COUNTY, NEVADA for WALKER LANE MINERALS CORP. Signed by: FRED H. BROWN, PGeo Senior Resource Geologist, GRC Nevada Inc. J. RICARDO GARCIA, PEng Corporate Chief Engineer, Gold Resource Corp. BARRY D. DEVLIN, PGeo Vice President, Exploration, Gold Resource Corp. JOY L. LESTER, SME-RM Chief Geologist, Gold Resource Corp. and Gold Resource Corp. and GRC Nevada Inc. Technical Staff Effective Date: December 31, 2017 REPORT ON THE RESERVE ESTIMATE & FEASIBILITY STUDY FOR THE ISABELLA PEARL PROJECT, NEVADA TABLE OF CONTENTS 1 SUMMARY …………………………………………………………………………………………………………………………14 1.1 Introduction and Purpose ...…………………………………………………………………………………14 1.2 Property Description and Ownership .………………………………………………………………………14 1.3 Geology and Mineralization …………………………………………………………………………...........15 1.4 Exploration and Mining History .…………………………………………………………………………………..15 1.5 Metallurgical Testing and Process Design Criteria .…………………………………………..…16 1.6 Economic Mineralized Material .…………………………………………………………………………………..18 1.7 Mineral Reserve Estimate .…………………………………………………………………………………..19 1.8 Mining Methods ………………………………………………………………………………………………..20 1.9 Mineral Processing and Recovery Methods …………………………………………………………..22 1.10 Project Infrastructure ………………………………………………………………………………………………..23 1.11 Environmental Studies and Permitting ……………………………………………………………………….25 1.12 Capital and Operating Costs ……………………………………………………………………………………26 1.13 Economic Analysis ...……………………………………………………………………………………………..27 1.14 Conclusions and Recommendations ....……………………………………………………………………29 2 INTRODUCTION …………………………………………………………………………………………………………….34 2.1 Terms of Reference and Purpose of Report …………………………………………...……………..34 2.2 Qualifications of Qualified Persons ……………………………………………………………………….34 2.3 Details of Inspection ………………………………………………………………………………………………..35 2.4 Sources of Information ………………………………………………………………………………………………..36 2.5 Effective Date …………………………………………………………………………………………………………….36 2.6 Units of Measure ………………………………………………………………………………………………..36 3 RELIANCE ON OTHER EXPERTS ………………………………………………………………………………………………..37 4 PROPERTY DESCRIPTION AND LOCATION ……………………………………………………………………….38 4.1 Property Location ………………………………………………………………………………………………..38 4.2 Mineral Titles …….………………………………………………………………………………………………………40 4.3 Royalties, Agreements and Encumbrances …………………………………………………………..41 4.4 Environmental Liabilities and Permitting …………………………………………………………..41 4.4.1 Environmental Liabilities ……………………………………………………………………….41 4.4.2 Required Permits and Status ……………………………………………………………………….42 4.5 Other Significant Factors and Risks ……………………………………………………………………….43 5 ACCESSIBILITY, CLIMATE, LOCAL RESOURCES, INFRASTRUCTURE AND PHYSIOGRAPHY …………44 2 REPORT ON THE RESERVE ESTIMATE & FEASIBILITY STUDY FOR THE ISABELLA PEARL PROJECT, NEVADA 5.1 Topography, Elevation and Vegetation ……………………………………………………………………….44 5.2 Accessibility and Transportation to the Property ………………………………………………44 5.3 Climate …………………………………………………………………………………………………………………………45 5.4 Sufficiency of Surface Rights ……………………………………………………………………………………45 5.5 Infrastructure Availability and Sources ……………………………………………………………………….46 5.5.1 Power …………………………………………………………………………………………………………….46 5.5.2 Water …………………………………………………………………………………………………………….46 5.5.3 Mining Personnel ……………………………………………………………………………………46 5.5.4 Potential Tailings Storage Areas ……………………………………………………………………….47 5.5.5 Potential Waste Disposal Areas ……………………………………………………………………….47 5.5.6 Potential Heap Leach Pad Areas …………………………………………………………..47 5.5.7 Potential Processing Plant Sites ……………………………………………………………………….47 6 HISTORY …………………………………………………………………………………………………………………………48 6.1 Prior Ownership and Ownership Changes …………………………………………………………..48 6.2 Exploration and Development Results of Previous Owners ………………………………….48 6.3 Historical Mineral Resource and Reserve Estimates ………………………………………………49 6.4 Historical Production ………………………………………………………………………………………………..51 7 GEOLOGICAL SETTING AND MINERALIZATION ……………………………………………………………………….52 7.1 Regional Geology ………………………………………………………………………………………………..52 7.2 Local and Property Geology ……………………………………………………………………………………54 7.2.1 Lithology ………………………………………………………………………………………………..57 7.2.2 Structural Geology ……………………………………………………………………………………57 7.2.3 Alteration ………………………………………………………………………………………………..58 7.3 Isabella Pearl Mineralized Zones…………………………………………………………………………………..60 7.3.1 Extents and Continuity ……………………………………………………………………………………61 8 DEPOSIT TYPE …………………………………………………………………………………………………………………………62 9 EXPLORATION …………………………………………………………………………………………………………………………65 9.1 Relevant Exploration Work ……………………………………………………………………………………65 9.1.1 Exploration by TXAU…………………………………………………………………………………………65 9.1.2 Exploration by WLMC…………………........................................................................65 9.2 Significant Results and Interpretation ……………………………………………………………………….66 10 DRILLING …………………………………………………………………………………………………………………………68 10.1 Type and Extent ………………………………………………………………………………………………..68 10.2 Procedures …………………………………………………………………………………………………………….70 3 REPORT ON THE RESERVE ESTIMATE & FEASIBILITY STUDY FOR THE ISABELLA PEARL PROJECT, NEVADA 10.2.1 RC Drilling ………………………………………………………………………………………………..70 10.2.2 Core Drilling ………………………………………………………………………………………………..71 10.2.3 Downhole Surveying ……………………………………………………….…………………………..72 10.3 Interpretation and Relevant Results ……………………………………………………………………….73 11 SAMPLE PREPARATION, ANALYSIS AND SECURITY …………………………………………………………..74 11.1 Mine Development Associates (2013) ……………………………………………………………………….74 11.1.1 Security Measures ……………………………………………………………………………………74 11.1.2 Sample Preparation for Analysis …………………………………………………………..74 11.1.2.1 RC Drilling Sampling…………………………………………………………………75 11.1.2.1.1 RC Drilling Sample Contamination……………………………….76 11.1.2.2 Core Sampling………………………………………………………………………….76 11.1.3 Sample Analysis ……………………………………………………………………………………78 11.1.4 Quality Assurance/Quality Control Procedures ………………………………………………78 11.1.4.1 Combined Metals-Homestake QA/QC Programs …………78 11.1.4.2 TXAU QA/QC Programs …………………………………………………………..83 11.2 WLMC (2016 to Present) ………………………………………………………………………………….100 11.2.1 Security Measures ………………………………………………………………………………….100 11.2.2 Sample Preparation and Analysis …………………………………………………………100 11.2.3 Quality Assurance/Quality Control Procedures …………………………………………….101 11.4 Opinion on Adequacy ………………………………………………………………………………………………102 12 DATA VERIFICATION …………………………………………………………………………………………………………..103 12.1 Procedures …………………………………………………………………………………………………………..103 12.2 Opinion on Data Adequacy ………………………………………………………………………………….103 13 MINERAL PROCESSING AND METALLURGICAL TESTING …………………………………………….104 13.1 Metallurgical Overview ………………………………………………………………………………………………104 13.2 Mineralogy and Metallurgical Ore Types …………………………………………………………105 13.3 Previous Metallurgical Test Work Programs………………………………………………………………..106 13.3.1 Combined Metals-Homestake Joint-Venture Metallurgical Test Work ……….106 13.3.2 TXAU Metallurgical Test Work ……………………………………………………………………..108 13.3.2.1 Isabella Results ……………………………………………….………………….…111 13.3.2.2 Pearl Results ……………………………………………………………………..112 13.3.2.3 Discussion of ROM Results …………………………………………….113 13.4 WLMC Metallurgical Ore Characterization Test Work Programs ………………………………..113 13.4.1 Location of WLMC Metallurgical Test Drill Hole Samples ……………………113 4 REPORT ON THE RESERVE ESTIMATE & FEASIBILITY STUDY FOR THE ISABELLA PEARL PROJECT, NEVADA 13.4.2 Results of WLMC Metallurgical Test Drill Hole Samples ………………………………..116 13.4.2.1 Cyanide Bottle Roll Tests …………………………………………….117 13.4.2.2 Head Screen Analysis …………………………………………………………119 13.4.2.3 Column Leach Test Work……………………………………………………….122 13.5 Discussion of Metallurgical Test Gold Recovery Curves …………………………………………….125 13.5.1 Discussion of Bottle Roll Test Gold Recovery Curves ………………………………..125 13.5.2 Discussion of Column Leach Test Gold Recovery Curves ………………………………..127 13.6 Process Selection and Design Parameters …………………………………………………………129 14 ECONOMIC MINERALIZED MATERIAL……………………………………………………………………………………..131 14.1 Introduction ……………………………………………………………………………………………………….….131 14.2 Database …………………………………………………………………………………………………………..132 14.2.1 Drill Data ………………………………………………………………………………………………132 14.3 Bulk Density …………………………………………………………………………………………………………..134 14.4 Wireframe Modeling ………………………………………………………………………………………………135 14.4.1 Topography ………………………………………………………………………………………………135 14.4.2 Gridded Surfaces ……………………………………………………………………………….…136 14.4.3 Mineralization Envelopes ………………………………………………………………..……136 14.5 Compositing ………………………………………………………………………………………………………..…138 14.6 Exploratory Data Analysis ………………………………………………………………………………….138 14.7 Treatment of Extreme Values ………………………………………………………………………………….142 14.8 Continuity Analysis ………………………………………………………………………………………………144 14.9 Block Model …………………………………………………………………………………………………………..144 14.10 Estimation and Classification ………………………………………………………………………………….145 14.11 Economic Mineralized Material Estimate……………………………………………………………………146 14.12 Mineralized Material Estimate Sensitivity …………………………………………………………148 14.13 Opinion on Adequacy ………………………………………………………………………………………………148 14.14 Validation …………………………………………………………………………………………………………..149 14.15 Risk Factors …………………………………………………………………………………………………………..150 15 MINERAL RESERVE ESTIMATE ………………………………………………………………………………………………152 15.1 Reserve