Slide 1: Island Gold District Site Tour
Magino Mill Magino Open Pit Island Gold Mill Island Gold Portal Island Gold Shaft Area Island Gold District Site Tour June 24-25, 2025 1
Slide 2: Cautionary notes
Cautionary notes This presentation, the information contained herein, any other materials provided in connection with this presentation and any oral remarks accompanying this presentation (collectively, the “Presentation”), has been prepared by Alamos Gold Inc. (“Alamos” or the “Company”) solely for
Slide 3: Introduction
Introduction John A. McCluskey President & CEO TSX:AGI | NYSE:AGI 3
Slide 4: Growing, diversified, intermediate gold producer
Growing, diversified, intermediate gold producer Fully funded Declining cost High quality, organic growth profile long-life assets in safe jurisdictions 2025E GOLD 2025E NET ASSET VALUE Qiqavik, Canada PRODUCTION1 A I S C / O Z 1,2,3 CANADIAN ASSETS4 Lynn Lake, Canada ~605k oz ~$1,275 89% Island Gol
Slide 5: Growing intermediate gold producer in low-risk jurisdictions
Growing intermediate gold producer in low-risk jurisdictions Uniquely positioned AGI - NYSE GDX GDXJ Gold (US$/oz) S&P 500 280% High-quality, long-life operations 240% Low-risk jurisdictions 200% Fully funded, high-return growth 160% 120% Expanding margins & profitability 80% Strong ongoing free cas
Slide 6: Long-term track record of creating value
Long-term track record of creating value Island Gold + Magino (US$M) Young-Davidson (US$M) $149 $546 $6.9B combined value created $4,608 $1,695 since acquisition through1,2: $1,367 $950 ✓ ongoing exploration success Acquisition Cost Island Gold (2017) & Magino Consensus NPV & Cumulative FCF Acquisit
Slide 7: Long-term track record of creating value through exploration
Long-term track record of creating value through exploration Growing, long-life Mineral Reserve base1 13,954 16,008 +65% +8M oz Magino increase in Mineral Reserves1, Mineral Resources1 delineated over past six years, net of over past six years 10,257 10,455 10,688 3.5M oz of depletion 9,702 9,726 9,
Slide 8: Development projects: High-return organic growth in low-risk jurisdictions
Development projects: High-return organic growth in low-risk jurisdictions 2025 2026 2027 2028 Longer-term Production at 2400 tpd Island Gold P3+ Expansion P3+ Construction >400k oz/year from Island Gold District Expansion to create one of lowest cost & most profitable gold mines in Canada June 2025
Slide 9: Island Gold District Life of Mine Plan (base case)
Island Gold District Life of Mine Plan (base case)1 Growing, long-life production • 411k oz per year over initial 12 years2, 43% increase from 2025 guidance • Will be among Canada’s largest gold mines post completion of Significant upside to be outlined in P3+ Expansion Expansion Study in Q4 2025 •
Slide 10: Island Gold District
Island Gold District One of largest, lowest-cost, & longest-life gold mines in Canada Annual production - 4th largest Top 3 Lowest Cost Profitability- Top 4 Annual Profitability 2025E Operation (US$M) (AISC3 Operation Owner Production1 2025E AISC1 Margin x annual Operation (koz) (US$/oz) production)
Slide 11: Island Gold District Growing Canadian production
Island Gold District Growing Canadian production 2025E Canadian Production1 Company (koz) Agnico Eagle 2,940 Alamos (post P3+ Expansion & Lynn Lake)2 770 Alamos – 2nd largest Alamos (post P3+ Expansion)2 594 gold producer in Canada Alamos 470 …. and growing IAMGOLD 398 New Gold 345 Newmont 315 Dhilm
Slide 12: Strong outlook
Strong outlook Growing, long-life Canadian production; declining cost profile 1,000 $1,281 $1,275 $1,400 ~1M oz 900 $1,200 longer-term potential production rate $1,175 800 $1,200 including Lynn Lake & further Expansion of Island Gold District, ~76% growth from 2024 Production (000 oz Au) 700 600 $1,
Slide 13: Fully funded growth with strong ongoing free cash flow
Fully funded growth with strong ongoing free cash flow Consolidated free cash flow outlook (US$M)1,2 Strong ongoing free cash flow $600 while funding high-return growth $500 $400 Significant free cash flow $300 growth 2026 onward driven by completion of growth projects $200 $100 Phase 3+ Expansion (
Slide 14: Island Gold District – site tour overview
Island Gold District – site tour overview 2022 2025 Austin Hemphill General Manager TSX:AGI | NYSE:AGI 14
Slide 15: Safety Guidelines
Safety Guidelines Underground and surface safety requirements: The personal protection equipment provided to you is required in all areas: 1. Tag in prior to going underground • Coveralls/Vests 2. Do not exit from vehicles in motion • Safety boots 3. Use 3 points of contact rule when entering/exitin
Slide 16: Table of Contents
Table of Contents 01 Island Gold District Overview 02 Current Operations ▪ Overview ▪ Mining ▪ Processing 03 Base Case LOM Plan ▪ Overview & economics ▪ Capital 04 Phase 3+ Expansion ▪ Overview & progress 05 Expansion Study Preview 06 Exploration 07 Appendix TSX:AGI | NYSE:AGI 16
Slide 17: Island Gold District – overview
Island Gold District – overview Location: Ontario, Canada - east of Dubreuilville, 83 km northeast of Wawa Ownership: 100% interest Land package: 59,900 hectares Island Gold Magino Operation: • Underground, mill • Open pit, mill • Initial production Jun 2023 • Commercial production Oct 2007 • Commer
Slide 18: Island Gold District – history
Island Gold District – history 2007 2017 2019 • Phase I Expansion PEA to 1,100 2023 2025 Island Gold began Phase II Expansion • June – Base Case tpd published (1,200 tpd) permit Nov 1st - Commercial commercial production LOM plan released • Alamos acquires Richmont amendment received production decl
Slide 19: Regional map - highly productive gold mining district
Regional map - highly productive gold mining district Detour Lake, Agnico Eagle Island Gold District located within Michipicoten Greenstone belt Hoyle Pond, Discovery Silver Corp. Understanding of gold Bell Creek, Pan American Silver endowment in belt rapidly Fox Complex, McEwen evolving supported b
Slide 20: ESG – low GHG emission intensity & decreasing
ESG – low GHG emission intensity & decreasing Low GHG emissions intensity1 • 57% below industry average currently • 29% decrease through completion of Phase 3+ Expansion & connection of Magino mill to grid power in 2026 0.9 0.79 0.8 0.7 tCO2e/oz produced 0.6 0.5 -29% 0.4 0.34 0.3 0.24 0.2 0.1 0 1 Se
Slide 21: ESG – Safety – strong trend & performance
ESG – Safety – strong trend & performance Safety Focus on proactive wellness measures Lost Time Injury Frequency Rate Employee Wellness program 0.18 0.17 o Mental health 0.16 0.15 o On-site physiotherapy 0.14 Zero 0.12 o Ergonomic assessments & injury prevention lost time injuries 0.1 0.08 since 202
Slide 22: ESG – Social – key focus on all stakeholders
ESG – Social – key focus on all stakeholders Social All employees as of December 31, 2024 >900 ~$28M 32% Local National 32% Alamos employees across spent with local of workforce local Island Gold District suppliers in 2024 (Dubreuilville, Wawa & 68% White River) Fostering positive relationships with
Slide 23: Overview of current operation
Overview of current operation TSX:AGI | NYSE:AGI 23
Slide 24: Gold production (000 oz Au)
Growing deposit supporting multi-phase expansion 200 $1,800 188 180 $1,500 160 150 Gold production (000 oz Au) $1,452 141 139 140 134 131 $1,200 Mine-site AISC (US$/oz)1 120 $1,185 $1,199 $1,136 106 99 $1,017 100 $900 83 $918 $863 80 $745 $781 $600 60 55 $656 $660 $599 42 40 34 $300 20 0 $0 2013 201
Slide 25: Strong ongoing cash flow generation funding expansion
Strong ongoing cash flow generation funding expansion $257 $182 $173 $165 $148 $133 $101 $76 $65 $59 $53 $41 $15 $26 $10 -$2 -$9 -$27 -$33 -$28 -$42 -$43 -$66 -$69 -$68 -$81 -$120 -$157 -$233 -$285 3 4 2015A 2016A 2017A 2018A 2019A 2020A 2021A 2022A 2023A 2024A 1 2 Total capital (US$m) Operating cas
Slide 26: Island Gold underground
Island Gold underground Ongoing exploration success driving growth in size & quality Significant Mineral Reserve & Resource growth since 2017 Acquisition +207% Mineral Reserves (k oz) 18 M&I Mineral Resources (k oz) 6,400 Inferred Mineral Resources (k oz) Mineral Reserve grade 1,329 16 5,400 Inferre
Slide 27: Island Gold underground
Island Gold underground One of Canada’s highest-grade & fastest growing underground gold mines 14 Higher Reserve Grade Eagle River 12 Island Gold (2024) 2 Proven and probable Reserves grade (g/t) Island Gold (June 2025) Island Gold (2023) 10 Island Gold (2016) Macassa Westwood 8 Brucejack Island Gol
Slide 28: Island Gold District – Base Case Life of Mine Plan
Island Gold District – Base Case Life of Mine Plan Growing, long-life, low-cost operation – with significant upside 600 $1,600 Island Gold @ 2,400 tpd over first 12 years: Stockpile processing: Average production: 411k oz; Mine-site AISC1,2: $915/oz Avg production: 90k oz $1,400 500 Mine-site AISC1,
Slide 29: Growing valuation
Growing valuation … with further upside to be outlined within Expansion Study Consensus NPV growth Base Case LOM NPV (US$M)1 (US$M) $6,667 +713% Significant upside within Q4 2025 Expansion Study $4,477 • Conversion & incorporation of $4,079 large Mineral Resource at Island Gold & Magino • Potential
Slide 30: Current operation – mining
Current operation – mining TSX:AGI | NYSE:AGI 30
Slide 31: Island Gold underground – mining
Island Gold underground – mining Mining method East • Longitudinal retreat long-hole open stoping (modified Avoca) • Transverse mining in wider zones • Alimak mining in western block • Mining rate 1,200 – 1,400 tpd Production fleet • 20x u/g Haul Trucks (AD30 & MT42) • 15x u/g LHD’s (scoops: 6yd and
Slide 32: Island Gold underground
Island Gold underground Mining – longitudinal retreat stope sequence Current mining practice – outside in As Mining Moves Deeper – Centre Out Stope Sequence • Currently, stopes mined longitudinally from sill extremities towards the centre • As the ore body grows and mining progresses deeper, a more
Slide 33: Island Gold underground 2025 production plan
Island Gold underground 2025 production plan 1040 Development 1050 Shaft Station 1095 Stope TSX:AGI | NYSE:AGI 33 33
Slide 34: Magino open pit – mining
Magino open pit – mining Mining method • Conventional shovel-truck open pit mining • Drilling and blasting configured to support 10 metre benches Production fleet Truck Loading Equipment Haul Trucks • 2x PC3000 – 19-21 yd Shovels • 15x HD1500 – 139 tonne (wet) • 1x PC2000 – 16-18 yd Shovel • 3x HD60
Slide 35: Magino open pit mining
Magino open pit mining Implementation of best practices driving improvement Fleet Optimization Mining Best Practices Implemented • Implementation of the Fleet Management System • Improved blasting techniques • Truck load counts automated & GPS tracked • Implementation of software to predict blast •
Slide 36: Ore & Waste mined (tpd)
Magino open pit mining Implementation of best practices driving improvement Total ore & waste mined (tpd) Ore & grades mined 60,000 0.95 1.00 16,000 0.90 50,000 14,000 0.77 0.76 0.73 0.80 Ore & Waste mined (tpd) Mined Grade (g/t Au) 40,000 12,000 Ore Mined (tpd) 10,000 0.60 30,000 8,000 0.40 20,000
Slide 37: Magino open pit 2025 production plan
Magino open pit 2025 production plan TSX:AGI | NYSE:AGI 37 37
Slide 38: Current operation – processing
Current operation – processing TSX:AGI | NYSE:AGI 38
Slide 39: Magino mill - overview
Magino mill - overview Key improvements: Primary Crusher Secondary Crusher Q3 2024: ✓ Secondary crusher replaced ✓ Successful batch test of lower grade Island Gold ore Q4 2024: ✓ Primary crusher & grizzly panel replaced Q1 2025: ✓ Transfer chute & ore handling system optimized April 2025: ✓ Successf
Slide 40: Magino mill
Magino mill Component changes & ongoing optimization driving improvement Ore & grades milled (tpd) Recoveries (%) 10,000 1.20 1.10 95.7% 9,000 94.5% 94.3% Average 92.5% 93.3% 0.92 1.00 recoveries: 8,000 0.89 0.86 94% 0.82 7,000 0.80 6,000 5,000 0.60 4,000 0.40 3,000 2,000 0.20 1,000 0 0.00 1 2 1 Q3
Slide 41: Combined milling rates nearing 11,200 tpd target
Magino mill Combined milling rates nearing 11,200 tpd target Ore milled (tpd) Island Gold District Target: 12,000 ~11,200 tpd • Combined milling rates between Island Gold & Magino mills nearing 11,200 tpd target 11,000 10,000 • Priority is to ensure higher-grade Island 9,000 Gold ore is processed 8,
Slide 42: Processing
Processing Integration of Island Gold ore Magino Haul Road • Haul road from Phase 3+ shaft area to Magino mill completed in June 2025 • Ore will be hauled from Island Gold portal followed by shaft site once expansion complete in H2 2026 • Distance from shaft to Magino mill is 6.5 kilometres by road
Slide 43: Magino mill expansion – significant long-term upside potential
Island Gold District Magino mill expansion – significant long-term upside potential Magino Mine Magino Mill Island Gold Mine Open pit mill feed (tpd) Total milling rate (tpd) Underground mining rate (tpd) 2024 10,000 10,000 IG mill 1,200 2025 10,000 11,200 1,200 2026+ 10,000 12,400 2,400 18,000 – 20
Slide 44: Processing – Magino mill flowsheet for expansion to 12,400 tpd
Processing – Magino mill flowsheet for expansion to 12,400 tpd Key improvements • Underground crushing of Island Gold ore • Pebble crusher & auxiliary mill added to grinding circuit • Installation of four additional leach tanks providing 48 hours of residence AUXILIARY MILL time • New building housi
Slide 45: Processing – expansion of Magino mill to 12,400 tpd
Processing – expansion of Magino mill to 12,400 tpd New mill building New components will support 12,400 tpd … with expansion potential up to 20,000 tpd • New mill building designed to accommodate addition of Additional SAG & ball mill leach tanks • Additional leach tanks can be added to support pot
Slide 46: Tailings – sufficient capacity for Base Case & Expansion Plan
Tailings – sufficient capacity for Base Case & Expansion Plan Magino – Tailings Management Facility (TMF) • Location – west of the Magino open pit • Design – downstream • Capacity – permitted under Federal EIS to 150 Mt • Current tailings needs: 81 Mt based on existing Mineral Reserves at Island Gol
Slide 47: Site power overview - grid power to supply all site needs
Site power overview - grid power to supply all site needs Current (2025) Future (Post P3+ at 12.4k tpd) Backup generator capacity Grid Power Grid Power Grid Power CNG Plant CNG Plant (44kV) (115kV) (44kV) 14 MW 19.5 MW 47 MW1 19.5 MW 14 MW (80MW ultimate capacity) Total Power Supply 33.5 MW 66.5 MW
Slide 48: Island Gold District Life of Mine Plan (base case)
Island Gold District Life of Mine Plan (base case) Chris Bostwick Austin Hemphill Nathan Bourgeault SVP, Technical Services General Manager Technical Services Manager Engineering TSX:AGI | NYSE:AGI 48
Slide 49: Base case Life of Mine Plan – assumptions
Base case Life of Mine Plan – assumptions Base case assumptions: Significant upside potential within Q4 2025 Expansion plan: • Total Mineral Reserves: 6.3M oz2 • Large Mineral Resource base – significant portion expected to convert to Reserves within Expansion • Island Gold: 4.1M oz3 Study through o
Slide 50: Base case Life of Mine – low-cost, long-life, significant upside
Base case Life of Mine – low-cost, long-life, significant upside Mill throughput tpd 12,400 Total production (life of mine) 000 oz Au 6,112 411k oz Mine life Years 20 Average production (life of mine) 000 oz Au 306 Average annual production over first 12 years1 Average production (12 yr avg 2026+) 1
Slide 51: Mineral Reserve & Resource update as of December 31, 2024
Mineral Reserve & Resource update as of December 31, 2024 Resource conversion at Island Gold drives 80% increase in Reserves June 2025 Update February 2025 Update Change % Tonnes Grade Ounces Tonnes Grade Ounces Tonnes Grade Ounces (000’s) (g/t Au) (000’s) (000’s) (g/t Au) (000’s) (000’s) (g/t Au) (
Slide 52: Island Gold underground – Mineral Reserves & Resources (Dec. 31, 2024)
Island Gold underground – Mineral Reserves & Resources (Dec. 31, 2024) February 2025 Update TSX:AGI | NYSE:AGI 52
Slide 53: Island Gold underground – Mineral Reserves & Resources (Dec. 31, 2024)
Island Gold underground – Mineral Reserves & Resources (Dec. 31, 2024) June 2025 Update TSX:AGI | NYSE:AGI 53
Slide 54: Island Gold District Mineral Reserves and Resources
Island Gold District Mineral Reserves and Resources Island Gold Mine1 Magino Mine2 Mineral Reserves (k oz) M&I Mineral Resources (k oz) Inferred Mineral Resources (k oz) 7,000 6,000 6,000 1,329 5,000 5,000 3,774 1,049 1,177 1,191 4,000 4,000 3,000 3,000 1,905 1,756 601 2,000 4,107 2,000 1,000 2,285
Slide 55: Island Gold underground Mining
Island Gold underground Mining Overview of Base Case LOM Plan: • Shaft operation • Paste backfill • Longitudinal retreat LHOS – unchanged • Increased development rates will support expanding operation TSX:AGI | NYSE:AGI 55
Slide 56: Island Gold Underground development
Island Gold Underground development Total Development Metres 16,000 14,000 12,000 ~10km/yr average development at 2,400 tpd 10,000 8,000 6,000 4,000 2,000 0 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037 2038 Increased development rates relative to P3+ Expansion supporting: • Growt
Slide 57: Island Gold underground Mining ramp up schedule – ore & grades mined
Island Gold underground Mining ramp up schedule – ore & grades mined 2,800 14.0 Avg LOM grade: 2,400 12.0 10.85 g/t Au 2,000 10.0 Grade mined, g/t Au Ore mined, tpd 1,600 8.0 1,200 6.0 800 4.0 400 2.0 0 0.0 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037 2038 2039 Ore mined, tpd Gra
Slide 58: Magino open pit Mining schedule – ore & grades mined
Magino open pit Mining schedule – ore & grades mined 1.20 75,000 Avg LOM grade: 0.92 g/t Au 1.00 Ore and Waste mined (tpd) 60,000 Grade mined (g/t Au) 0.80 45,000 0.60 30,000 0.40 15,000 0.20 0 0.00 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037 2038 2039 Waste mined, tpd Ore mined
Slide 59: Island Gold District Processing rate & blended grade profile
Island Gold District Processing rate & blended grade profile 3.50 12,500 3.00 10,000 2.50 Milled grade (g/t Au) Ore milled (tpd) 7,500 2.00 1.50 5,000 1.00 2,500 0.50 0 0.00 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037 2038 2039 2040 2041 2042 2043 2044 2045 Magino ore miled (tpd
Slide 60: Island Gold District - annual gold production
Island Gold District - annual gold production 411k oz +43% 20 year average annual production over initial increase from 2025 guidance mine life with upside given ongoing 12 years1, 306k oz over the life of mine Mineral Reserve & Resource growth 1 500 411k oz avg production 450 400 Gold Production, 0
Slide 61: Mine-site all-in sustaining costs – first quartile
Mine-site all-in sustaining costs – first quartile Mine-site all-in sustaining costs (US$/oz)1 $915/oz average mine-site AISC1 19% decrease from 2025 2025E Initial 12 years Average LOM2 post expansion2 guidance $1,125 $915 $1,003 $2,000 $1,800 $1,600 Mine-site AISC (US$/oz)1,2 $1,400 Island Gold @2,
Slide 62: Unit operating costs – underground Mining
Unit operating costs – underground Mining Unit Mining Cost (C$/tonne) $180 2025E Average LOM $166 $124 $160 Underground Mining Costs $140 (C$/t mined) $120 $100 $80 $60 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037 2038 2039 • Completion of shaft to drive 25% decrease in unit mini
Slide 63: Unit operating costs – processing
Unit operating costs – processing $28 Unit Processing Cost (C$/tonne) $26 2025E Average LOM $24.66 $16.74 $24 $22 Magino Milling Costs (C$/t milled) $20 $18 $16 $14 $12 $10 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037 2038 2039 2040 2041 2042 2043 2044 2045 • Transition of Magino
Slide 64: Unit costs & currency sensitivities
Unit costs & currency sensitivities Island Gold District LOM Cost Structure Unit Costs Lodging/Transportation 2025 Guidance Base Case LOM 6% per tonne1 Maintenance Mill Consumables 13% 5% Other 4% Open Pit Mining C$5.10 C$4.24 Fuel and gas 5% Underground Mining C$138 C$124 Mine Consumables Electrici
Slide 65: Island Gold District – LOM production & cost profile
Island Gold District – LOM production & cost profile 600 $1,600 Island Gold @ 2,400 tpd over first 12 years: Stockpile processing: Average production: 411k oz; Mine-site AISC1,2: $915/oz Avg production: 90k oz $1,400 500 Mine-site AISC1,2: $1,715/oz Gold production (000 oz Au) $1,200 Mine-site AISC
Slide 66: Base Case LOM Plan – cash flow profile at $2,400/oz Au
Base Case LOM Plan – cash flow profile at $2,400/oz Au $442M average annual free cash flow 1 $750 $558 $536 $550 $510 $506 $506 $434 $454 $386 $369 $401 $346 $350 $301 $233 $228 $138 $107 $108 $111 $114 $150 $68 -$50 -$250 -$450 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037 2038 2
Slide 67: Base Case LOM Plan – cash flow profile at $3,300/oz Au
Base Case LOM Plan – cash flow profile at $3,300/oz Au $664M average annual free cash flow 1 $950 $828 $794 $787 $784 $723 $750 $685 $640 $645 $597 $559 $550 $487 $442 $379 $353 $350 $204 $166 $162 $164 $169 $150 $114 -$50 -$250 -$450 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037
Slide 68: Base Case LOM – significant upside potential
Base Case LOM – significant upside potential After-tax NPV 5% (US$M)1 After tax NPV 5% (US$M)1 $7,236 $6,667 Gold price LOM $5,811 $2,000 $2,942 $5,098 After-tax NPV 5% $4,477 $2,400 (Base case2) $4,477 $2,750 $5,098 $2,942 $3,000 $5,811 $3,300 $6,667 $3,500 $7,236 $2,000 $2,400 $2,750 $3,000 $3,300
Slide 69: Base Case LOM – growth capital summary
Base Case LOM – growth capital summary Island Gold District • Remaining Phase 3+ Expansion growth capital Growth Capital Base Case LOM (as of Jan 1, 2025) estimated to be $349M as of Jan 2025 • Total Phase 3+ growth capital estimate at completion Remaining P3+ Expansion Capital $349 of $835M (5% inc
Slide 70: Base Case LOM – sustaining capital
Base Case LOM – sustaining capital (in US$M) Island Gold District Sustaining Capital Base Case LOM (as of Jan 1, 2025) Changes relative to P3+ Study Underground Capital Development $691 • Addition of Magino Open Pit Mobile Equipment and Maintenance $295 Open Pit Capitalized Stripping $241 • Increase
Slide 71: Phase 3+ Expansion – progress to date
Phase 3+ Expansion – progress to date John Fitzgerald SVP, Projects Trevor Gilchrist Project Director – Phase 3+ TSX:AGI | NYSE:AGI 71
Slide 72: Phase 3+ Expansion – significantly de-risked given progress to date
Phase 3+ Expansion – significantly de-risked given progress to date Project significantly de-risked ✓ Shaft surface infrastructure substantially complete ✓ Shaft sink 92% complete – current depth of 1,265 m Shaft area Paste plant ✓ Paste plant 71% complete ✓ Powerline project on track for completion
Slide 73: Progress to date – shaft site infrastructure substantially complete
Progress to date – shaft site infrastructure substantially complete ✓ Hoist house - substantially completed in Nov 2023 ✓ Propane storage - installation completed in Dec 2023 Headframe ✓ Warehouse - substantially completed in April 2024 ✓ E-house - electrical infrastructure required for shaft Admin
Slide 74: Progress to date – shaft site sink 92% complete
Progress to date – shaft site sink 92% complete Shaft sink at ~1,265 m by the end of May; Currently working on 1265L ~92% of ultimate planned depth of 1,379 m shaft station Shaft area – May 2025 1050L shaft station with galloway March 2025 TSX:AGI | NYSE:AGI 74
Slide 75: Progress to date – paste plant 71% complete
Progress to date – paste plant 71% complete Paste plant & paste backfill >2,400 tpd capacity • Increased mining recovery • Additional >140k oz gold recovered • Improvements in mining process • Faster stope cycling supporting higher mining rates • Increased geotechnical stability • Reduced tailings c
Slide 76: Shaft – hoisting plant – substantially complete
Shaft – hoisting plant – substantially complete • 2,000m design depth; initial sink to 1,379m • Ontario FOS all cases 5,500 tpd capacity at initial 1,379 m depth • 4200kW rating Production hoisting plant (ore & waste) 2,000 m hoisting design depth • 5m x 2m double drum • 2 x 15t skips at 15m/s on st
Slide 77: Shaft – headworks – substantially complete
Shaft – headworks – substantially complete Steel headframe • 59m overall • Sheave decks at 42m, 51m Hoist house • 20m x 40m main hoistroom • Two hoists co-located • Hoist and UG feed electrical room • Combined control room • Sinking compressor and laydown space Hoist drive cooling building Bin house
Slide 78: Shaft designed to accommodate future exploration success
Shaft designed to accommodate future exploration success TSX:AGI | NYSE:AGI 78
Slide 79: Scope changes to P3+ Expansion Study
Scope changes to P3+ Expansion Study • Island Gold crushing facility relocated from surface to underground • optimizing the flow of ore handling from the underground to the mill Crusher Station • reduce required hoisting house maintenance • crusher capacity 2,400 tpd per 12 hour shift • ore bin capa
Slide 80: Phase 3+ Expansion – project schedule & progress to date
Phase 3+ Expansion – project schedule & progress to date Phase 3+ Expansion projects % completion Start date Completion date Shaft & Shaft Surface Construction 84% Q1 2022 H2 2026 Complex Underground Ore and Engineering 90% Q3 2023 Q3 2025 Waste Handling System Construction 0% Q3 2025 Q3 2026 Engine
Slide 81: Phase 3+ Expansion – project construction schedule
Phase 3+ Expansion – project construction schedule Q4 2025 Q2 2026 H2 2026 shaft sinking to be completed completion of power line project initial production from shaft & expanded Magino mill 2022 2023 2024 2025 2026 Milestones Start Finish Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Slide 82: Regulatory Permitting
Regulatory Permitting All permits required for current operation in place Island Gold Magino ✓ Closure Plan Amendment for Phase III Expansion to ✓ Closure Plan Amendment – approved September 2024 2,000 tpd - approved March 2022 ✓ Mill – Federal EIS approved to 35k tpd processing rate ✓ Closure Plan
Slide 83: Expansion Study preview – Q4 2025
Expansion Study preview – Q4 2025 Luc Guimond Chief Operating Officer TSX:AGI | NYSE:AGI 83
Slide 84: Expansion Study preview
Expansion Study preview Significant upside to June 2025 Base Case LOM plan Upside to base case LOM Plan ✓ Potential mill expansion up to 20,000 tpd ✓ Increased mining & milling rates from Island Gold & Magino ✓ Conversion & incorporation of large Mineral Resource base ✓ Significant exploration upsid
Slide 85: Expansion Study preview
Expansion Study preview Significant upside to June 2025 Base Case LOM plan Key components of larger expansion already de-risked • Key permits in place • Mill permitted to operate at 35k tpd • Tailings facility permitted to contain 150M tonnes • Excess capacity within Phase 3+ Expansion • Excess capa
Slide 86: Excess hoisting capacity within shaft infrastructure
Excess hoisting capacity within shaft infrastructure Ore and Waste Mined (tpd) 6,000 5,500 tpd shaft capacity at 1,379m 5,000 depth 4,000 4,300 tpd average peak mining 3,000 rate 2027-2032 2,000 1,000 0 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037 2038 2039 Total Ore Mined (LOM)
Slide 87: Expansion Study preview Processing – potential expansion up to ~20,000 tpd
Expansion Study preview Processing – potential expansion up to ~20,000 tpd Current Expansion to 12,400 tpd Potential expansion up to ~20,000 tpd • Expansion Plan expected to include parallel circuit dedicated to processing blend of Island Gold & Magino ore • Crushing circuit to be significantly impr
Slide 88: Expansion Study preview Processing – potential expansion up to ~20,000 tpd
Expansion Study preview Processing – potential expansion up to ~20,000 tpd Expansion to 12,400 tpd Potential expansion up to ~20,000 tpd New mill building SAG & ball mill Earthworks for new mill building underway Thickener New leach tanks Additional leach tanks New Ore bins • Footprint of new mill b
Slide 89: Expansion Study preview Processing – potential expansion up to ~20,000 tpd
Expansion Study preview Processing – potential expansion up to ~20,000 tpd Expansion to 12,400 tpd Potential expansion up to ~20,000 tpd Additional leach tanks Additional CIP tanks Ball mill SAG mill • CIP tanks to be added for 12,400 tpd expansion sized to support processing rates of up to 20,000 t
Slide 90: Expansion Study preview Processing – potential expansion up to ~20,000 tpd
Expansion Study preview Processing – potential expansion up to ~20,000 tpd • Addition of gyratory crusher to support >20,000 tpd Gyratory crusher • Truck dump with permanent rock breaker allowing for direct tipping of ore • New ore bins to replace current tent configuration TSX:AGI | NYSE:AGI 90 90
Slide 91: Expansion Study preview Upside through conversion of large Mineral Resource base
Expansion Study preview Upside through conversion of large Mineral Resource base Island Gold Mine1 Magino Mine2 Mineral Reserves (k oz) M&I Mineral Resources (k oz) Inferred Mineral Resources (k oz) Base Case LOM Plan includes 7,000 Mineral Reserves only 6,000 1,329 5,000 1,049 1,191 4,000 Expansion
Slide 92: Expansion Study preview Upside through higher mining rates at Island Gold & Magino
Expansion Study preview Upside through higher mining rates at Island Gold & Magino Magino open pit Island Gold underground • Mining rates ~15k tpd ore > processing rate of 10k tpd • Growing Reserve & Resource base expected to support mining rates • Larger Mineral Reserve pit expected to support high
Slide 93: Significant exploration upside – Island Gold underground
Significant exploration upside – Island Gold underground Increasing grade & ounces per vertical metre below 1,000m level TSX:AGI | NYSE:AGI 93
Slide 94: Significant exploration upside – Island Gold underground
Significant exploration upside – Island Gold underground Increasing grade & ounces per vertical metre below 1,000m level High grade area 12,000 in lower east Limited18 drilling Current lowest zone completed below production horizon 15.53 1,500m 14.40 16level (1095L) 10,000 14.73 14 Ounces per Vertic
Slide 95: Expansion Study preview Longer-term upside through incorporation of regional exploration targets
Expansion Study preview Longer-term upside through incorporation of regional exploration targets Large land package with multiple past producing mines & high-grade gold occurrences Larger mill provides potential for multiple sources of higher-grade ore to be fed through centralized mill TSX:AGI | NY
Slide 96: Exploration
Exploration Scott R.G. Parsons VP, Exploration TSX:AGI | NYSE:AGI 96
Slide 97: Evolution of Island Gold – year-end 2016
Evolution of Island Gold – year-end 2016 (acquired November 2017) ER Mineral Reserves & Resources as of Dec 31, 2016 Category Tonnage Grade Au g/t Ounces Au Proven & 2,527,299 9.26 752,209 Probable Measured & 478,811 5.94 91,426 Indicated: Inferred: 3,041,836 10.18 995,717 TSX:AGI | NYSE:AGI 97
Slide 98: Island Gold Mine – Mineral Reserves & Resources as of December 31, 2019
Island Gold Mine – Mineral Reserves & Resources as of December 31, 2019 ER Mineral Reserves & Resources as of Dec 31, 2019 Category Tonnage Grade Au g/t Ounces Au Proven & 3,642,900 10.37 1,215,100 Probable Measured & 878,600 6.51 184,000 Indicated: Inferred: 5,392,300 13.26 2,298,000 TSX:AGI | NYSE
Slide 99: Island Gold –Mineral Reserve & Resources as of December 31, 2022
Island Gold –Mineral Reserve & Resources as of December 31, 2022 ER TSX:AGI | NYSE:AGI 99
Slide 100: Island Gold Mine – Mineral Reserves & Resources as of December 31, 2024
Island Gold Mine – Mineral Reserves & Resources as of December 31, 2024 June 2025 Update TSX:AGI | NYSE:AGI 100
Slide 101: Island Gold Mine – 2025 Mine Exploration Drilling
Island Gold Mine – 2025 Mine Exploration Drilling • 2025 Global Exploration budget is $72M • 2025 Exploration budget at Island is $27M and includes: • 41,500 m of UG exploration drilling • 18,000 m of surface exploration drilling • 18,000 m of surface delineation drilling at Magino • 10,000 m surfac
Slide 102: Island Gold Mine Exploration YTD 2025 - C/E1E Zones
Island Gold Mine Exploration YTD 2025 - C/E1E Zones TSX:AGI | NYSE:AGI 102 Jun 2023
Slide 103: Island Gold Mine Exploration YTD 2025 – Hanging Wall & Footwall Zones
Island Gold Mine Exploration YTD 2025 – Hanging Wall & Footwall Zones TSX:AGI | NYSE:AGI 103
Slide 104: Island Gold Mine – Delineation Drilling 2025
Island Gold Mine – Delineation Drilling 2025 • 30,800 m of UG delineation drilling in Q1 2025 • +13,000 m of surface delineation added in Q1 2025 2025 YTD highlights • 83.02 g/t Au (28.30 g/t cut) over 5.57 m (1160-625-11) • 55.63 g/t Au (40.25 g/t cut) over 6.36 m (1160-625-11) • 60.81 g/t Au (41.2
Slide 105: Island Gold Mine – Delineation Drilling Drillhole MH41-01
Island Gold Mine – Delineation Drilling Drillhole MH41-01 MH41-01 (June 2025) 1,468.27 – 1,477.91 meters = 9.64 meters (Core Length): • Delineation drill hole within high- grade Inferred Mineral Resources in Island East • The intersection contained several intervals with significant visible gold TSX
Slide 106: Magino Mine – Delineation Drilling 2025
Magino Mine – Delineation Drilling 2025 • 18,000 m of surface delineation drilling • Focused on conversion of Inferred Mineral Resources between the Mineral Reserve and Resource Pits TSX:AGI | NYSE:AGI 106
Slide 107: Island Gold Mine – Long-term Exploration Potential
Island Gold Mine – Long-term Exploration Potential C-Zone Potential Extension Island Gold Down-plunge Island Gold East/Down- South of Webb Lake Stock plunge TSX:AGI | NYSE:AGI 107
Slide 108: Longitudinal of Canadian underground gold deposits
Longitudinal of Canadian underground gold deposits Island Gold Mine Red Lake - Campbell La Ronde • Commercial Production 2007 • Commercial Production 1949 • Commercial Production 1988 • Historical Production 1.7M oz Au • Historical Production 20M oz Au • Historical Production 6M oz Au • Reserves 4.1
Slide 109: Island Gold Exploration Target – C-Zone South of Webb Lake Stock
Island Gold Exploration Target – C-Zone South of Webb Lake Stock TSX:AGI | NYSE:AGI 109
Slide 110: Island Gold Exploration Target – C-Zone South of Webb Lake Stock
Island Gold Exploration Target – C-Zone South of Webb Lake Stock TSX:AGI | NYSE:AGI 110
Slide 111: Island Gold Exploration Target – C-Zone South of Webb Lake Stock
Island Gold Exploration Target – C-Zone South of Webb Lake Stock TSX:AGI | NYSE:AGI 111
Slide 112: Island Gold Exploration Target – C-Zone South of Webb Lake Stock
Island Gold Exploration Target – C-Zone South of Webb Lake Stock TSX:AGI | NYSE:AGI 112
Slide 113: Island Gold Regional – North Shear Target
Island Gold Regional – North Shear Target TSX:AGI | NYSE:AGI 113
Slide 114: Island Gold Regional – North Shear Target
Island Gold Regional – North Shear Target TSX:AGI | NYSE:AGI 114
Slide 115: Island Gold Regional – Cline, Edwards, and Pick Mines
Island Gold Regional – Cline, Edwards, and Pick Mines TSX:AGI | NYSE:AGI 115
Slide 116: Island Gold Regional – Cline, Edwards, and Pick Mines
Island Gold Regional – Cline, Edwards, and Pick Mines TSX:AGI | NYSE:AGI 116
Slide 117: Consolidation of Michipicoten Greenstone Belt
Consolidation of Michipicoten Greenstone Belt Growing land package, with significant near mine & regional exploration potential across underexplored • 2017: Richmont Mines acquisition Michipicoten Greenstone Belt • 9,500 ha total • 2020: Trillium Mining acquisition • 5,400 ha (14,900 ha total) • 202
Slide 118: Island Gold Regional – Michipicton Greenstone Belt
Island Gold Regional – Michipicton Greenstone Belt • 60+ km strike along the most significant gold trend within the Michipicoten Greenstone Belt • Active exploration and drilling on several targets peripheral to Island Major 60+ km Gold Mine, including the high-grade Gold Trend Cline, Edwards, and P
Slide 119: Closing summary – Island Gold District
Closing summary – Island Gold District Attractive Base Case …. with significant upside Base Case LOM plan Expansion Study - Q4 2025 Longer-term growth potential Attractive long-life, low-cost operation Expected to outline significant upside Reflecting exploration upside • 411k oz average annual prod
Slide 120: Appendix
Appendix TSX:AGI | NYSE:AGI 120
Slide 121: 2025 guidance
2025 guidance 2025 Guidance 2024A Island Young- Mulatos District Lynn Lake Total Total Gold District Davidson Gold production (000 oz) 275 - 300 175 - 190 130 - 140 - 580 - 630 567 Total cash costs1 ($/oz) $725 - 775 $1,075 - 1,125 $925 - 975 - $875 - 925 $927 All-in sustaining costs1 ($/oz) $1,250
Slide 122: 2025 - 2027 guidance
2025 - 2027 guidance1 2025 2026 2027 Gold Production (000 oz) Island Gold District 275 - 300 330 - 355 375 - 400 Young-Davidson 175 - 190 180 - 195 180 - 195 Mulatos District 130 - 140 120 - 130 125 - 135 Total Gold Production (000 oz) 580 - 630 630 - 680 680 - 730 Total Cash Costs1 ($/oz) $875 - 92
Slide 123: Island Gold District - 2025 guidance
Island Gold District - 2025 guidance 2024A 2025E Guidance Q1 2025A Gold production (000 oz) 188.0 275-300 59.2 2025 production growth driven by Total cash costs, per ounce of gold sold1 $804 $725-775 $1,068 higher mining rates at Island Gold & Mine-site all-in sustaining costs, per oz of gold sold1,
Slide 124: Island Gold District Base Case LOM plan
Island Gold District Base Case LOM plan Detailed mine plan summary LOM 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037 2038 2039 2040 2041 2042 2043 2044 avg Underground ore mined (tpd) 2,148 1,319 1,914 2,405 2,399 2,400 2,400 2,400 2,399 2,400 2,400 2,400 2,353 2,304 1,713 1,018 -
Slide 125: Base case LOM – Total Mineral Reserves
Base case LOM – Total Mineral Reserves Tonnes Gold Grade Contained Gold Island Gold Cut-Off Grade Parameters (kt) (g/t) (koz) Parameter Units Value Island Gold Proven 821 11.82 312 Gold Price US$ $1,600 Probable 10,947 10.78 3,795 Sub-Total Underground 11,769 10.85 4,107 Stope Cut-off Grade g/t 3.78
Slide 126: Total Proven & Probable Mineral Reserves
Total Proven & Probable Mineral Reserves PROVEN AND PROBABLE GOLD RESERVES (as at December 31, 2024) Proven Reserves Probable Reserves Total Proven and Probable Tonnes Grade Ounces Tonnes Grade Ounces Tonnes Grade Ounces (000's) (g/t Au) (000's) (000's) (g/t Au) (000's) (000's) (g/t Au) (000's) Isla
Slide 127: Total Measured & Indicated Mineral Resources
Total Measured & Indicated Mineral Resources MEASURED AND INDICATED GOLD MINERAL RESOURCES (as at December 31, 2024) Measured Resources Indicated Resources Total Measured and Indicated Tonnes Grade Ounces Tonnes Grade Ounces Tonnes Grade Ounces (000's) (g/t Au) (000's) (000's) (g/t Au) (000's) (000'
Slide 128: Total Inferred Mineral Resources
Total Inferred Mineral Resources INFERRED GOLD MINERAL RESOURCES (as at December 31, 2024) Tonnes Grade Ounces (000's) (g/t Au) (000's) Island Gold 2,449 16.88 1,329 Magino 40,291 0.92 1,191 Total Island Gold District 42,740 1.83 2,520 Young-Davidson - Surface 31 0.99 1 Young-Davidson - Underground
Slide 129: Notes to Mineral Reserve and Resource estimates
Notes to Mineral Reserve and Resource estimates Qualified Persons Chris Bostwick, FAusIMM, Alamos Gold’s Senior Vice President, Technical Services, has reviewed and approved the scientific and technical information contained in this news release. Chris Bostwick is a Qualified Person within the meani
Slide 130: Cautionary Note to U.S. Investors
Cautionary Note to U.S. Investors All Resource and Reserve estimates included in this Presentation have been prepared in accordance with Canadian National Instrument 43-101 - Standards of Disclosure for Mineral Projects (“NI 43-101”) and the Canadian Institute of Mining, Metallurgy and Petroleum (th
Slide 131: Investor Relations contacts
SCOTT K. PARSONS, CFA SVP, Corporate Development & Investor Relations 416.368.9932 x 5439 ir@alamosgold.com KHALID ELHAJ, P.ENG., CFA VP, Business Development & Investor Relations 416.368.9932 x 5427 ir@alamosgold.com