Alamos Gold Inc. (TSX:AGI) (NYSE:AGI) reported new results from underground and surface drilling at the Island Gold Mine. Exploration drilling continues to extend high-grade gold mineralization across the Island Gold Deposit, as well as within several hanging wall and footwall structures. The ongoing success through 2024 is expected to drive another year of growth in Mineral Reserves and Resources within the year-end update to be released in February 2025.

“Our drilling program at Island Gold over the past year has been one of the most successful in the history of the asset in terms of the magnitude of high-grade intercepts across the lateral extent of the main deposit, and within the numerous newly defined hanging wall and footwall zones. We expect this to drive another year of growth in combined Mineral Reserves and Resources, marking the ninth consecutive year, with grades also increasing over that time frame. Island Gold has established itself as one of the highest-grade and fastest growing deposits in the world. With the main structure open laterally and down-plunge, and significant high-grade results being intersected within emerging and yet to be defined zones in proximity to the main structure, we see excellent potential for this pace of growth to continue,” said John A. McCluskey, President and Chief Executive Officer.

Island Gold Main zone exploration highlights: high-grade mineralization extended outside of Mineral Reserves and Resources in the E1E and C-Zones. These zones are the main structures which host the majority of currently defined Mineral Reserves and Resources at Island Gold. New highlights include¹:

• Island West (C-Zone)
  • 67.68 g/t Au (16.07 g/t cut) over 3.61 m (790-479-62);
  • 31.59 g/t Au (31.59 g/t cut) over 4.18 m (890-461-58);
  • 16.58 g/t Au (16.58 g/t cut) over 5.56 m (890-461-40);
  • 40.21 g/t Au (21.69 g/t cut) over 2.08 m (790-479-69);
  • 22.71 g/t Au (11.48 g/t cut) over 2.14 m (890-461-54); and
  • 20.09 g/t Au (20.09 g/t cut) over 2.13 m (1025-497-08).
• Island East (E1E-Zone)
  • 55.50 g/t Au (45.31 g/t cut) over 3.87 m (MH40-02);
  • 49.26 g/t Au (49.26 g/t cut) over 2.07 m (540-578-05);
  • 31.55 g/t Au (31.55 g/t cut) over 2.92 m (MH40-03); and
  • 26.25 g/t Au (26.25 g/t cut) over 2.57 m (540-578-08).

Island Gold Hanging Wall and Footwall exploration highlights: high-grade gold mineralization intersected within new and recently defined hanging wall and footwall zones across the main Island Gold Deposit. These zones represent significant opportunities to continue to grow near mine Mineral Reserves and Resources which are low-cost to develop and produce from, given their proximity to existing infrastructure. New highlights include¹:

Other Hanging Wall and Footwall intersections within yet to be defined zones (Unknown Zones): drilling continues to intersect high-grade mineralization beyond currently defined zones and in proximity to existing underground infrastructure. This includes drill hole 890-461-42 (584.20 g/t Au over 6.80 m), located 10 m north of the main C-Zone in Island West. These are part of more than 2,000 intersections above 3 g/t Au outside of existing Mineral Reserves and Resources in the hanging wall and footwall. Through additional drilling, there is excellent potential to define additional new zones supporting significant growth in near-mine Mineral Reserves and Resources. New highlights include²:

Footwall

• 584.20 g/t Au over 6.80 m (890-461-42);
• 129.76 g/t Au over 2.90 m (440-586-01);
• 58.77 g/t Au over 4.90 m (890-461-17);
• 114.22 g/t Au over 2.20 m (890-461-34);
• 92.85 g/t Au over 2.20 m (890-461-56);
• 46.83 g/t Au over 4.20 m (890-461-47);
• 25.95 g/t Au over 6.10 m (890-461-57);
• 40.59 g/t Au over 3.85 m (890-461-54);
• 61.33 g/t Au over 2.35m (490-450-06);
• 24.16 g/t Au over 5.95 m (890-461-54);
• 12.12 g/t Au over 9.55 m (945-624-48);
• 31.23 g/t Au over 3.40 m (890-461-52);
• 32.57 g/t Au over 3.05 m (560-481-17);
• 33.23 g/t Au over 2.75 m (890-461-33); and
• 44.94 g/t Au over 2.00 m (890-461-40).

Hanging Wall

• 158.03 g/t Au over 2.00 m (490-450-05);
• 46.75 g/t Au over 6.10 m (850-475-13);
• 38.44 g/t Au over 5.35 m (1025-517-34);
• 30.95 g/t Au over 6.25 m (890-461-57);
• 38.63 g/t Au over 3.80 m (890-461-52);
• 37.61 g/t Au over 3.05 m (850-475-27);
• 28.05 g/t Au over 3.90 m (890-461-10); and
• 22.74 g/t Au over 3.75 m (580-463-29).

Island Gold East delineation and definition drilling highlights: ongoing drilling focused on the conversion of Mineral Resources to Mineral Reserves from the 945, 1040, and 1130-levels has defined wider, higher-grade zones over a 150 m by 250 m area within the Island Main structure. New highlights include¹:

• 31.42 g/t Au (22.16 g/t cut) over 17.87 m (945-624-52);
• 37.92 g/t Au (21.18 g/t cut) over 13.46 m (1130-623-34);
• 23.57 g/t Au (21.93 g/t cut) over 19.34 m (1130-623-25);
• 37.07 g/t Au (31.64 g/t cut) over 7.94 m (1130-623-35); and
• 8.72 g/t Au (8.72 g/t cut) over 18.65 m (945-624-50).

¹ All reported composite intervals are calculated true width of the mineralized zones. Drillhole composite intervals reported as “cut” may include higher grade samples which have been cut to: Island West and Island Main (C-zone) @ 225 g/t Au; Island Main and East (E1E Zone) @ 185 g/t Au; E1D Zone @ 100 g/t; B-Zone, E1D1 and NS1 @ 90 g/t Au; NTH3 @ 60 g/t; D1 and G1 @ 45 g/t Au, DN, DN2, NS2 and NTH zones @ 35 g/t Au.

² All reported composite intervals are core length, true width is unknown at this time, and gold grades are reported as uncut.

New highlight intercepts can be found in Tables 1 and 2, and in Figures 1 and 2 at the end of this news release.

2024 Exploration Drilling Program

A total of $19 million was budgeted for exploration at Island Gold in 2024, up from $14 million in 2023. The focus of the program was to define new Mineral Reserves and Resources in proximity to existing production horizons and infrastructure. A total of 50,416 m of underground exploration drilling was completed in 185 holes in 2024, relative to a planned 41,000 m. Additionally, 9,849 m of surface exploration drilling was completed in 11 holes. This drilling focused on evaluating targets across the strike extent of the main Island Gold Deposit (E1E and C-Zones), as well as expanding newly defined zones in the hanging wall and footwall of Island Gold.

In addition to the exploration budget, 36,686 m of underground delineation drilling was completed in 155 holes in 2024, which focused on the conversion of the large Mineral Resource base to Mineral Reserves.

Island West

Underground Exploration Drilling

High-grade gold mineralization further extended and has now been defined 150 m to the west of the 490-level, and up-plunge from existing Mineral Reserves and Resources in the middle portion of Island West. Drilling is being conducted from the 490-level, 790-level, and the 1025-level exploration drifts, between vertical depths of 400 m and 1,200 m.

New highlights in the C-Zone include (Figure 1, Tables 1 and 2) ¹:

• Island West (C-Zone)
  • 67.68 g/t Au (16.07 g/t cut) over 3.61 m (790-479-62);
  • 31.59 g/t Au (31.59 g/t cut) over 4.18 m (890-461-58);
  • 16.58 g/t Au (16.58 g/t cut) over 5.56 m (890-461-40);
  • 40.21 g/t Au (21.69 g/t cut) over 2.08 m (790-479-69);
  • 22.71 g/t Au (11.48 g/t cut) over 2.14 m (890-461-54);
  • 20.09 g/t Au (20.09 g/t cut) over 2.13 m (1025-497-08); and
  • 12.36 g/t Au (7.05 g/t cut) over 2.70 m (790-479-58).

Island West Hanging Wall Zones

In addition to testing the main Island Gold structure (C-Zone), underground exploration drilling continued to target high-grade gold mineralization in sub-parallel and perpendicular structures in the hanging wall from the 490, 890, 900, and 1025-levels.

NS1 and NS2 Hanging Wall Zones

The NS1 zone is a north-striking structure with a high-angle orientation relative to the C-Zone that was discovered in early 2023. The first stopes were mined from the NS1 zone during the second half of 2023 and it continues to be actively mined, highlighting the near-term opportunities within these hanging wall and footwall zones.

The NS2 zone is a new sub-parallel north-strike structure discovered 200 m east of the NS1 zone. To date, this zone has been defined over a vertical extent of 300 m, and an average strike of 100 m.

In addition, several other north-striking high-angle structures have been identified across the deposit from reinterpretation of historical hanging wall drilling, which will be further evaluated as underground exploration drilling advances.

New highlights from the Island West Hanging Wall zones include (Figure 2, Table 1):

Island East

Surface and Underground Exploration Drilling

Underground drilling continues to extend high-grade gold mineralization within gaps between Mineral Reserves and Resources in upper to middle portions of Island East.

In addition, surface drilling continues to define and expand high-grade gold mineralization in the middle to lower portions of Island East and Island Main. This includes within a large 200 m by 400 m gap in Mineral Reserves and Resources in Island East between 1,100 m and 1,300 m depths, as well as in Island Main between 1,300 m and 1,400 m depths (holes MH40-02 (55.50 g/t Au (45.31 g/t cut) over 3.87 m) and MH 40-03 (31.55 g/t Au (31.55 g/t cut) over 2.92 m)). Following the completion of the surface drilling program, additional drilling will be completed as underground development and drill platforms are established closer to this area.

New highlights in the E1E-Zone include (Figure 1, Tables 1 and 2):

• Island East (E1E-Zone)
  • 55.50 g/t Au (45.31 g/t cut) over 3.87 m (MH40-02);
  • 49.26 g/t Au (49.26 g/t cut) over 2.07 m (540-578-05);
  • 31.55 g/t Au (31.55 g/t cut) over 2.92 m (MH40-03);
  • 26.25 g/t Au (26.25 g/t cut) over 2.57 m (540-578-08); and
  • 18.39 g/t Au (18.39 g/t cut) over 2.16 m (MH39-04).

Underground Delineation Drilling

Delineation and definition drilling focused on Mineral Resource conversion in Island East from the 945, 1040, and 1130-levels continues to define wide, higher-grade zones in Island East. This includes a 150 m by 250 m zone with significantly higher than average grades and widths relative to the rest of the Island Gold deposit. This is expected to support further growth in high-grade Mineral Reserves. New highlights include¹:

• 31.42 g/t Au (22.16 g/t cut) over 17.87 m (945-624-52);
• 37.92 g/t Au (21.18 g/t cut) over 13.46 m (1130-623-34);
• 23.57 g/t Au (21.93 g/t cut) over 19.34 m (1130-623-25);
• 37.07 g/t Au (31.64 g/t cut) over 7.94 m (1130-623-35); and
• 8.72 g/t Au (8.72 g/t cut) over 18.65 m (945-624-50).

Island East Footwall Zones

Underground exploration drilling continues to target high-grade gold mineralization in structures in the footwall from the 840 and 945-levels that were defined and included in year-end 2023 Mineral Reserves and Resources. Ongoing drilling in 2024 continues to confirm the continuity and extend high-grade gold mineralization within the E1D1 and NTH3 zones, located 10 m and 60 m from the E1E-Zone, respectively.

New highlights from the Island East Footwall zones include (Figure 2, Table 1):

E1D1 Zone

• 63.51 g/t Au (14.53 g/t cut) over 2.09 m (945-624-65A);
• 26.38 g/t Au (26.38 g/t cut) over 2.04 m (945-624-71); and
• 6.90 g/t Au (6.90 g/t cut) over 6.06 m (945-624-62).

NTH3 Zone

• 37.02 g/t Au (29.46 g/t cut) over 2.42 m (840-572-56);
• 29.63 g/t Au (8.91 g/t cut) over 2.50 m (840-572-48);
• 30.21 g/t Au (15.61 g/t cut) over 1.99 m (840-572-46); and
• 15.87 g/t Au (15.87 g/t cut) over 2.50 m (840-572-45).

As with the hanging wall and footwall zones in Island West, these footwall zones in Island East highlight the potential to add high-grade Mineral Reserves and Resources in proximity to existing production horizons and infrastructure which would be low-cost to develop and mine.

Other Zones

The majority of Island Gold’s Mineral Reserves and Resources and main production horizons are hosted in the C/E1E structure. The Island Gold Deposit also consists of a growing number of sub-parallel and high-angle mineralized structures outside of the main C/E1E-Zone. As underground development advances, these sub-parallel hanging wall and footwall structures can be targeted and defined with step-out drilling from underground drill platforms.

These zones, and other targets within the hanging wall and footwall, represent significant opportunities to continue defining additional high-grade Mineral Reserves and Resources in proximity to existing underground infrastructure. In 2023, approximately 70% of the growth in Mineral Reserves and Resources (before depletion) came from additions in recently defined hanging wall and footwall zones. These additions continue to enhance the ounce per vertical metre profile and provide additional operational flexibility with multiple mining horizons from the same lateral development levels.

The following are highlights of new hanging wall and footwall intersections from underground exploration drilling where the geometry and continuity are not yet established (“Unknown Zone”). These are part of more than 2,000 intersections above 3 g/t Au within recently defined and yet to be defined zones in the hanging wall and footwall. These intersections are outside of existing Mineral Reserves and Resources, highlighting the opportunity for significant near-mine additions as ongoing drilling further defines these areas.

New highlights include (reported composite intervals are uncut and as core length, as true width is unknown at this time) (Table 1):

Footwall

• 584.20 g/t Au over 6.80 m (890-461-42);
• 129.76 g/t Au over 2.90 m (440-586-01);
• 58.77 g/t Au over 4.90 m (890-461-17);
• 114.22 g/t Au over 2.20 m (890-461-34);
• 92.85 g/t Au over 2.20 m (890-461-56);
• 46.83 g/t Au over 4.20 m (890-461-47);
• 25.95 g/t Au over 6.10 m (890-461-57);
• 40.59 g/t Au over 3.85 m (890-461-54);
• 61.33 g/t Au over 2.35m (490-450-06);
• 24.16 g/t Au over 5.95 m (890-461-54);
• 12.12 g/t Au over 9.55 m (945-624-48);
• 31.23 g/t Au over 3.40 m (890-461-52);
• 32.57 g/t Au over 3.05 m (560-481-17);
• 33.23 g/t Au over 2.75 m (890-461-33);
• 44.94 g/t Au over 2.00 m (890-461-40);
• 40.01 g/t Au over 2.10 m (890-461-54);
• 32.35 g/t Au over 2.50 m (890-461-17);
• 15.53 g/t Au over 5.00 m (790-479-51);
• 23.74 g/t Au over 3.20 m (890-461-23);
• 19.50 g/t Au over 3.75 m (890-461-33);
• 9.68 g/t Au over 6.90 m (890-461-48);
• 15.59 g/t Au over 4.25 m (890-461-23);
• 24.70 g/t Au over 2.45 m (1025-497-13);
• 11.03 g/t Au over 4.95 m (890-461-08); and
• 15.30 g/t Au over 3.30 m (MH39-06).

Hanging Wall

• 158.03 g/t Au over 2.00 m (490-450-05);
• 46.75 g/t Au over 6.10 m (850-475-13);
• 38.44 g/t Au over 5.35 m (1025-517-34);
• 30.95 g/t Au over 6.25 m (890-461-57);
• 38.63 g/t Au over 3.80 m (890-461-52);
• 37.61 g/t Au over 3.05 m (850-475-27);
• 28.05 g/t Au over 3.90 m (890-461-10);
• 22.74 g/t Au over 3.75 m (580-463-29);
• 26.64 g/t Au over 2.60 m (580-463-08);
• 15.12 g/t Au over 4.25 m (890-461-55A);
• 14.00 g/t Au over 4.10 m (1025-517-25);
• 22.53 g/t Au over 2.40 m (1025-517-25); and
• 26.93 g/t Au over 2.00 m (580-463-33).

Qualified Persons

Scott R.G. Parsons, P.Geo., FAusIMM, Alamos Gold’s Vice President, Exploration, has reviewed and approved the scientific and technical information contained in this news release. Scott R.G. Parsons is a “Qualified Person” as defined by Canadian Securities Administrators’ National Instrument 43-101 – Standards of Disclosure for Mineral Projects.

Exploration programs at the Island Gold Mine are directed and supervised by Tyler Poulin, P.Geo., Geology Superintendent at the Island Gold Mine. Tyler Poulin is a “Qualified Person” as defined by Canadian Securities Administrators’ National Instrument 43-101 – Standards of Disclosure for Mineral Projects.

Quality Assurance and Quality Control

Alamos Gold maintains an internal Quality Assurance / Quality Control program at the Island Gold Mine to ensure sampling and analysis of all exploration work is conducted in accordance with best practices.

Access to the Island Gold Mine is controlled by security personnel. Drill core is logged and sampled at core logging facilities within the mine site under the supervision of a Qualified Geologist. A geologist marks the individual samples for analysis, and sample intervals, sample numbers, standards and blanks are entered into the database. Exploration core is cut in half using an electric core saw equipped with a diamond tipped blade. One half of the core is placed into a plastic sample bag and sealed with zip ties in preparation for shipment. The other half of the core is returned to the core box and retained for future reference. Approximately 20% of all delineation core is cut and stored, and the entire core sample is sent for analysis on all definition programs.

The samples are placed in large heavy-duty nylon reinforced Fabrene bags, which are identified and sealed before being placed on pallets. The core samples are picked up at the mine site and mine samples are delivered to AGAT and Actlabs laboratories, and regional samples are delivered to ALS laboratory, all located in Thunder Bay, Ontario.

Gold is analyzed by a 50 grams fire assay with an Atomic Absorption (AA) finish. Mine samples greater than 10.0 g/t Au, and regional samples greater than 5.0 g/t Au are re-analyzed using gravimetric finish methods. AGAT, Actlabs and ALS are certified laboratories and have internal quality control programs that include insertion of reagent blanks, reference materials, and pulp duplicates.

The Corporation inserts QC samples (blanks and reference materials) at regular intervals to monitor laboratory performance. Cross check assays are completed on a regular basis in a secondary accredited laboratory. The Island Gold Mine QA/QC procedures are more completely described in the August 29, 2022 Technical Report filed on SEDAR+ (www.sedarplus.ca).

About Alamos

Alamos is a Canadian-based intermediate gold producer with diversified production from three operations in North America. This includes the Young-Davidson mine and Island Gold District in northern Ontario, Canada, and the Mulatos District in Sonora State, Mexico. Additionally, the Company has a strong portfolio of growth projects, including the Phase 3+ Expansion at Island Gold, and the Lynn Lake project in Manitoba, Canada. Alamos employs more than 2,400 people and is committed to the highest standards of sustainable development.

Table 1: Island Gold – Previously Unreleased Select Composite Intervals from Underground and Surface Mine Exploration Drilling

Composite intervals greater than 3 g/t Au weighted average, capping values:

Island West and Island Main (C-zone) @ 225 g/t Au; Island Main and East (E1E Zone) @ 185 g/t Au; E1D Zone @ 100 g/t Au; B Zone, E1D1 zone and NS1 @ 90 g/t Au; NTH3 Zone @ 60 g/t Au; D1 and G1 @ 45 g/t Au, DN, DN2, NS2, and NTH zone @ 35 g/t Au.

Table 2: Island Gold – Previously Unreleased Select Composite Intervals from Underground Delineation Drilling

Composite intervals greater than 100 g*m g/t Au weighted average, capping values:

Island Main and East (E1E Zone) @ 185 g/t Au

Table 3: Underground exploration and delineation, and surface exploration drill holes; azimuth, dip, drilled length, and collar location at surface (UTM NAD83).

Note: UTM mine surface elevation 393 m

Figure 1: Island Gold Mine – C/E1E Longitudinal: New Underground Exploration Drilling Highlights: C & E1E-Zone

Figure 2: Island Gold Mine – New Underground Exploration Drilling Highlights: Hanging Wall & Footwall Zones