Alamos Gold Expands High-Grade Mineralization at Puerto Del Aire

Drilling at Cerro Pelon is following up on wide, high-grade underground oxide and sulphide intersections previously drilled below the Cerro Pelon open pit. The 2024 drill program has successfully expanded high-grade mineralization beyond the historical drilling in multiple oxide and sulphide zones. Additionally, surface drilling has extended higher-grade mineralization across multiple zones within the PDA area.

Ongoing exploration success is expected to support further growth in Mineral Reserves and Resources at PDA, and an initial underground Mineral Resource at Cerro Pelon with the year-end update expected to be released in February 2025. The success at both deposits highlights the significant exploration upside opportunities to the PDA project, with an initial development plan to be released today after market close.

Cerro Pelon exploration highlights: step-out drilling below the previously mined oxide deposit has identified significant high-grade feeder structures that range in size from 45 to 125 metres ("m") in width, and up to 170 m vertically. The top portion of the mineralized zones contain oxide mineralization including the historical intercept of 15.35 g/t Au (14.04 g/t cut) over 25.04 m true width (15PEL012) drilled in 2015. Cerro Pelon is located nine kilometres ("km") by road from the planned PDA mill and represents a potential source of additional high-grade mill feed. New highlights include¹:

• 5.45 g/t Au over 27.90 m, including 31.07 g/t Au over 1.25 m (24PEL048);
• 12.47 g/t Au (9.41 g/t cut) over 6.46 m, including 58.10 g/t Au (40.00 g/t cut) over 1.09 m (24PEL048);
• 4.79 g/t Au over 15.82 m (24PEL071);
• 4.46 g/t Au over 15.40 m (24PEL051);
• 5.64 g/t Au over 12.16 m (24PEL059);
• 5.77 g/t Au over 9.81 m (24PEL067); and
• 4.01 g/t Au over 13.85 m (24PEL054).
  

PDA exploration highlights: additional high-grade gold mineralization extended beyond Mineral Reserves and Resources within the GAP-Victor, PDA3 and PDA Extension zones. New highlights include¹:

GAP-Victor Zone

• 5.43 g/t Au over 18.05 m (23MUL278);
• 23.60 g/t Au over 3.00 m (24MUL302);
• 27.62 g/t Au (23.06 g/t cut) over 2.25 m (24MUL332);
• 12.28 g/t Au over 4.95 m (24MUL363); and
• 5.77 g/t Au over 8.65 m (24MUL304).
  

PDA3 Zone

• 3.03 g/t Au over 28.40m (24MUL347); and
• 6.63 g/t Au over 5.50 m (24MUL365).

PDA Extension Zone

• 36.20 g/t Au over 0.90 m (24MUL341);
• 3.51 g/t Au over 5.05 m (24MUL315); and
• 4.16 g/t Au over 4.20 m (24MUL283).
  

¹All reported composite widths are estimated true width of the mineralized zones. Drillhole composite gold grades reported as "cut" at PDA and Cerro Pelon include higher grade samples which have been cut to 40 g/t Au.

"Our PDA development plan to be released later today is expected to outline another attractive, high-return project that will nearly triple the current mine life of the Mulatos District. The development plan will be based on PDA's current Mineral Reserve of one million ounces which had more than doubled over the previous two years. Our continued exploration success at PDA in 2024 highlights the significant upside potential to the project through further growth in higher-grade Mineral Reserves and Resources," said John A. McCluskey, President and Chief Executive Officer.

"The addition of a mill to process higher-grade sulphide mineralization will also open up additional opportunities within the Mulatos District, including Cerro Pelon, where we expect to declare an initial Mineral Resource in early 2025. With PDA and Cerro Pelon open in multiple directions, and a number of other promising targets, there is excellent potential to continue defining higher-grade Mineral Reserves and Resources across the Mulatos District," Mr. McCluskey added.

New highlight intercepts can be found in Table 1, and in Figures 2 through 4 at the end of this news release.

2024 Exploration Budget - Mulatos

A total of $19 million has been budgeted at Mulatos for exploration in 2024, consistent with 2023. The near-mine and regional drilling program is expected to total 55,000 m, including 27,000 m of surface exploration drilling at PDA and the surrounding area. Exploration activities are focused on following up on a successful 2023 exploration program that drove a 33% increase in Mineral Reserves at PDA to 1.0 million ounces (5.4 mt grading 5.61 g/t Au), compared to 2022, with grades also increasing 16%.

Given the ongoing growth of the PDA deposit, other higher-grade sulphide opportunities are being targeted within the Mulatos District, including below the previously mined Cerro Pelon open pit.

Cerro Pelon

The 2024 drill program at Cerro Pelon is focused on defining high-grade mineralization below the previously mined open pit where wide, high-grade mineralization was intersected across multiple drill holes between 2008 to 2017. Previously reported highlights from 2015 and 2016 include²:

• 15.35 g/t Au (14.04 g/t cut) over 25.04 m (15PEL012);
• 9.16 g/t Au over 19.22 m (16PEL018);
• 10.36 g/t Au over 17.40 m (15PEL020);
• 6.95 g/t Au over 13.53 m (15PEL069); and
• 13.47 g/t Au over 3.47 m (15PEL085).
  

²All reported historic composite widths are estimated true width of the mineralized zones. Drillhole composite gold grades reported as "cut" include higher grade samples which have been cut to 40 g/t Au.

An initial 2,000 m of drilling was planned at Cerro Pelon in 2024. Given the success to date, 8,864 m has been completed and is reported in this release. High-grade gold and silver mineralization is localized in pipe-like geometries at the intersection of >500 m long north north-west structures, and >400 m long east north-east structures, thought to represent high sulphidation feeder zones. Drilling to date has defined higher-grade mineralization 50 to 200 m below the Cerro Pelon pit bottom. New highlights from this drilling include:

• 5.45 g/t Au over 27.90 m, including 31.07 g/t Au over 1.25 m (24PEL048);
• 12.47 g/t Au (9.41 g/t cut) over 6.46 m, including 58.10 g/t Au (40.00 g/t cut) over 1.09m (24PEL048);
• 4.79 g/t Au over 15.82 m (24PEL071);
• 4.46 g/t Au over 15.40 m (24PEL051);
• 5.64 g/t Au over 12.16 m (24PEL059);
• 5.77 g/t Au over 9.81 m (24PEL067);
• 4.01 g/t Au over 13.85 m (24PEL054);
• 4.42 g/t Au over 9.55 m (24PEL066);
• 7.13 g/t Au over 4.22 m (24PEL046);
• 4.46 g/t Au over 5.07 m (24PEL070);
• 4.09 g/t Au over 5.05 m (24PEL066);
• 3.22 g/t Au over 6.38 m (24PEL074); and
• 4.73 g/t Au over 3.57 m (24PEL054).
  

An objective of the 2024 drilling campaign is to establish the shape and extent of the high-grade gold and silver mineralization within the zones. Drilling to date has defined more than five pipes with lateral dimensions ranging from 150 m by 100 m, to 75 m by 60 m, and vertical extents ranging between 40 m and 150 m. There is significant potential to expand the mineralization in all directions with limited drilling completed beyond the five feeders identified to date.

PDA - GAP-Victor, PDA3 and PDA Extension Zones

PDA is a higher-grade underground deposit located adjacent to the main Mulatos pit and is comprised of multiple mineralized zones including PDA, Gap, Victor, and Estrella (Figure 4). Ongoing exploration success has driven substantial growth in the deposit over the past three years. In 2023, Mineral Reserves increased 33% to 1.0 million ounces at 16% higher grades of 5.61 g/t Au. Over the past two years, PDA's Mineral Reserves have more than doubled, at 20% higher grades. Combined Mineral Reserves and Resources also increased 26% in 2023 to total 1.2 million ounces.

Given ongoing exploration success in 2024, and with the deposit open in multiple directions, there is excellent potential for this growth to continue. Over the past three years, discovery costs at PDA have averaged $19 per ounce.

PDA is located adjacent to the Mulatos pit with the underground deposit expected to be accessed from a ramp and development drifts from within the pit. A development plan for PDA will be released after market close today, based on Mineral Reserves as of the end of 2023. Ongoing exploration success at PDA and Cerro Pelon in 2024 represents upside to the project.

The initial focus of the surface exploration program in 2024 has been on the GAP-Victor zones, and in the relatively untested area between the PDA zones and GAP-Victor with 14,513 m of drilling completed to date. Another 10,937 m of drilling was completed within PDA3 and PDA Extension. New highlights from results received since the year end 2023 Mineral Reserves and Resources include:

GAP-Victor Zone

• 5.43 g/t Au over 18.05 m (23MUL278);
• 23.60 g/t Au over 3.00 m (24MUL302);
• 27.62 g/t Au (23.06 g/t cut) over 2.25 m (24MUL332);
• 12.28 g/t Au over 4.95 m (24MUL363);
• 5.77 g/t Au over 8.65 m (24MUL304);
• 16.40 g/t Au over 1.50 m (24MUL294);
• 20.10 g/t Au over 1.20 m (24MUL304);
• 12.60 g/t Au over 1.90 m (24MUL273);
• 14.90 g/t Au over 1.50 m (24MUL314);
• 5.40 g/t Au over 4.10 m (24MUL323);
• 8.97 g/t Au over 2.10 m (24MUL290);
• 3.04 g/t Au over 6.00 m (24MUL302);
• 15.90 g/t Au over 1.10 m (24MUL291); and
• 5.36 g/t Au over 3.25 m (24MUL291).

PDA3 Zone

• 3.03 g/t Au over 28.40 m (24MUL347);
• 6.63 g/t Au over 5.50 m (24MUL365); and
• 8.09 g/t Au over 2.70 m (24MUL349).
  

PDA Extension

• 36.20 g/t Au over 0.90 m (24MUL341);
• 3.51 g/t Au over 5.05 m (24MUL315); and
• 4.16 g/t Au over 4.20 m (24MUL283).
  

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 Mulatos are directed and supervised by Michele Cote, P.Geo., Alamos Gold's Chief Exploration Geologist, Corporate. Michele Cote 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 (QA/QC) program at Mulatos to ensure sampling and analysis of all exploration work is conducted in accordance with best practices.

Access to the Mulatos Property is controlled by security personnel. The drill core is logged and sampled at the core logging facility within the mine site under the supervision of a Qualified Geologist. A geologist marks the individual samples for analysis, and sample intervals, based on lithology and alteration, standards and blanks are entered into the database. The 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 micropore sample bag and sealed with a cable tie in preparation for shipment. The other half of the core is returned to the core box and retained for future reference. The samples are placed in large heavy-duty nylon reinforced micropore bags, which are identified and sealed before being dispatched. The core samples are picked up at the mine site and delivered to Bureau Veritas Commodities Canada Ltd. laboratory in Hermosillo, Mexico.

Gold is analyzed by 30 grams Lead Collection Fire Assay Fusion (FA) that ends with an Atomic Absorption Spectroscopy finish (AAS). Samples greater than 5.0 g/t Au are re-analyzed starting again with a FA process but ending with a gravimetric finish (GRAV). Bureau Veritas is an ISO/IEC 17025 accredited laboratory and has internal quality control ("QC") programs that include insertion of reagent blanks, reference materials, and pulp duplicates that are in line with normal requirements, as well as participating in yearly proficiency tests to evaluate lab performance.

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.

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. The Company's shares are traded on the TSX and NYSE under the symbol "AGI".

FOR FURTHER INFORMATION, PLEASE CONTACT:

The TSX and NYSE have not reviewed and do not accept responsibility for the adequacy or accuracy of this release.

Cautionary Note

This news release includes certain statements that constitute forward-looking information within the meaning of applicable Canadian and U.S. securities laws ("forward-looking statements"). All statements in this news release other than statements of historical fact, which address events, results, outcomes or developments that Alamos expects to occur are forward-looking statements. Forward-looking statements are generally, but not always, identified by the use of forward-looking terminology such as "continue", "ongoing", "expect", "plan", "estimate", "target", "objective", "budget", "opportunity" or "potential" or variations of such words and phrases and similar expressions or statements that certain actions, events or results "may", "could", "would", "might" or "will" be taken, occur or be achieved or the negative connotation of such terms.

Such statements in this news release include, without limitation, statements with respect to planned exploration programs and focuses, potential drilling targets, results and related expectations, costs and expenditures, project economics, gold grades, mineralization, expected growth of PDA deposit, expected method of mining the PDA deposit and the intended method of processing ore from the PDA deposit, planned PDA mill, initial underground Mineral Resource at Cerro Pelon, mine life and expected mine life extension at Mulatos, returns to stakeholders and other information that is based on forecasts and projections of future operational, geological or financial results, estimates of amounts not yet determinable and assumptions of management.

A Mineral Resource that is classified as "inferred" or "indicated" has a great amount of uncertainty as to its existence and economic and legal feasibility. It cannot be assumed that any or part of an "Indicated Mineral Resource" or "Inferred Mineral Resource" will ever be upgraded to a higher category of Mineral Resource. Investors are cautioned not to assume that all or any part of mineral deposits in these categories will ever be converted into Proven and Probable Mineral Reserves.

Alamos cautions that forward-looking statements are necessarily based upon several factors and assumptions that, while considered reasonable by management at the time of making such statements, are inherently subject to significant business, economic, technical, legal, political and competitive uncertainties and contingencies. Known and unknown factors could cause actual results to differ materially from those projected in the forward-looking statements, and undue reliance should not be placed on such statements and information.

These factors and assumptions include, but are not limited to: the actual results of current exploration activities; conclusions of economic and geological evaluations; changes in project parameters as plans continue to be refined; any impacts of any illnesses, diseases, epidemics or pandemics on operations and the broader market, including the nature and duration of any regulatory responses; state and federal orders or mandates (including with respect to mining operations generally or auxiliary businesses or services required for the Company's operations) in Mexico; changes in national and local government legislation, controls or regulations; failure to comply with environmental and health and safety laws and regulations; labour and contractor availability (and being able to secure the same on favourable terms); ability to sell or deliver gold doré bars; disruptions in the maintenance or provision of required infrastructure and information technology systems; fluctuations in the price of gold or certain other commodities such as, diesel fuel, natural gas, and electricity; operating or technical difficulties in connection with mining or development activities, including geotechnical challenges and changes to production estimates (which assume accuracy of projected ore grade, mining rates, recovery timing and recovery rate estimates and may be impacted by unscheduled maintenance); changes in foreign exchange rates (particularly the Canadian dollar, U.S. dollar, and Mexican peso); the impact of inflation; employee and community relations; litigation and administrative proceedings; disruptions affecting operations; availability of and increased costs associated with mining inputs and labour; delays in the development or updating of mine and/or development plans; changes that may be required to the intended method of accessing and mining the deposit at Puerto Del Aire and changes related to the intended method of processing any ore from the deposit at Puerto Del Aire; inherent risks and hazards associated with mining and mineral processing including environmental hazards, industrial accidents, unusual or unexpected formations, pressures and cave-ins; the risk that the Company's mines may not perform as planned; uncertainty with the Company's ability to secure additional capital to execute its business plans; the speculative nature of mineral exploration and development, risks in obtaining and maintaining necessary licenses, permits and authorizations, contests over title to properties; expropriation or nationalization of property; political or economic developments in Canada or Mexico and other jurisdictions in which the Company may carry on business in the future; increased costs and risks related to the potential impact of climate change; the costs and timing of construction and development of new deposits; risk of loss due to sabotage, protests and other civil disturbances; the impact of global liquidity and credit availability and the values of assets and liabilities based on projected future cash flows; and business opportunities that may be pursued by the Company.

For a more detailed discussion of such risks and other factors that may affect the Company's ability to achieve the expectations set forth in the forward-looking statements contained in this news release, see the Company's latest 40-F/Annual Information Form and Management's Discussion and Analysis, each under the heading "Risk Factors", available on the SEDAR website at www.sedarplus.ca or on EDGAR at www.sec.gov. The foregoing should be reviewed in conjunction with the information and risk factors and assumptions found in this news release.

The Company disclaims any intention or obligation to update or revise any forward-looking statements, whether written or oral, or whether as a result of new information, future events or otherwise, except as required by applicable law.

Note to U.S. Investors - Mineral Reserve and Resource Estimates

Unless otherwise indicated, all Mineral Resource and Mineral Reserve estimates included in this news release have been prepared in accordance with National Instrument 43-101 - Standards of Disclosure for Mineral Projects ("NI 43-101") and the Canadian Institute of Mining, Metallurgy and Petroleum (the "CIM") - CIM Definition Standards on Mineral Resources and Mineral Reserves, adopted by the CIM Council, as amended (the "CIM Standards"). NI 43-101 is a rule developed by the Canadian Securities Administrators, which established standards for all public disclosure an issuer makes of scientific and technical information concerning mineral projects. Mining disclosure in the United States was previously required to comply with SEC Industry Guide 7 ("SEC Industry Guide 7") under the United States Securities Exchange Act of 1934, as amended. The U.S. Securities and Exchange Commission (the "SEC") has adopted final rules, to replace SEC Industry Guide 7 with new mining disclosure rules under sub-part 1300 of Regulation S-K of the U.S. Securities Act ("Regulation S-K 1300") which became mandatory for U.S. reporting companies beginning with the first fiscal year commencing on or after January 1, 2021. Under Regulation S-K 1300, the SEC now recognizes estimates of "Measured Mineral Resources", "Indicated Mineral Resources" and "Inferred Mineral Resources". In addition, the SEC has amended its definitions of "Proven Mineral Reserves" and "Probable Mineral Reserves" to be substantially similar to international standards.

Investors are cautioned that while the above terms are "substantially similar" to CIM Definitions, there are differences in the definitions under Regulation S-K 1300 and the CIM Standards. Accordingly, there is no assurance any mineral reserves or mineral resources that the Company may report as "proven mineral reserves", "probable mineral reserves", "measured mineral resources", "indicated mineral resources" and "inferred mineral resources" under NI 43-101 would be the same had the Company prepared the mineral reserve or mineral resource estimates under the standards adopted under Regulation S-K 1300. U.S. investors are also cautioned that while the SEC recognizes "measured mineral resources", "indicated mineral resources" and "inferred mineral resources" under Regulation S-K 1300, investors should not assume that any part or all of the mineralization in these categories will ever be converted into a higher category of mineral resources or into mineral reserves. Mineralization described using these terms has a greater degree of uncertainty as to its existence and feasibility than mineralization that has been characterized as reserves. Accordingly, investors are cautioned not to assume that any measured mineral resources, indicated mineral resources, or inferred mineral resources that the Company reports are or will be economically or legally mineable.

Table 1: Select Composite Intervals from new Surface Exploration Drilling and PDA and Cerro Pelon

Composite intervals greater than 3 g/t Au weighted average, capping values 40 g/t Au.

Note : 24PEL series composites are calulated using a 2 g/t Au cut-off with up to 7 m of internal waste.
23MUL and 24MUL series composites are calculated using a 2 g/t Au cut-off with up to 5 m of internal waste.

Table 2: Surface drill holes; azimuth, dip, drilled length, and collar location at surface
(UTM Zone 12 NAD27)

Figure 1: Puerto Del Aire and Cerro Pelon Location Map, Mulatos District

Figure 2: Cerro Pelon - New Exploration Highlights, Plan View

Figure 3: Cerro Pelon - Cross Section Through Mineralization with New Exploration Highlights

Figure 4: Puerto Del Aire - New Exploration Highlights, Plan View

Photos accompanying this announcement are available at

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