Fortuna intersects 31.3 g/t gold over 12.0 meters from the Karakara Prospect at the Diamba Sud Gold Project

VANCOUVER, June 25, 2024 - Fortuna Mining Corp. (NYSE: FSM | TSX: FVI) is pleased to provide an update on its exploration programs at the Diamba Sud Gold Project in Senegal.

Paul Weedon, Senior Vice President of Exploration at Fortuna, commented, "Drilling at Karakara continues to improve our understanding of the prospect's potential, returning several high-grade intercepts including a highlight intersection of 31.3 g/t Au over an estimated true width of 12.0 meters in drill hole DSDD243. The exploration team is looking forward to utilizing the improved understanding of the geological controls on gold mineralization to further advance the regional exploration programs." Mr. Weedon concluded, "Our focus has now moved towards progressing some of the many satellite opportunities at Diamba Sud, with highly encouraging, early-stage results such as 8.9 g/t Au over an estimated true width of 27.7 meters returned from drill hole DSR680 at Western Splay, and 2.9 g/t Au over an estimated true width of 15.3 meters returned from drill hole DSDD262 at Kassasoko. These prospects represent new opportunities for additional ounces and continue to highlight the prospectivity of the wider Diamba Sud Gold Project."

Diamba Sud Gold Project, Senegal

Drilling at Diamba Sud has continued with the focus moving to testing and upgrading several key high priority satellite prospects (refer to Figure 1), including Western Splay and Kassasoko, as well as further work to improve the definition and understanding of the mineralization controls at Bougouda and Karakara. An additional 20,665-meter, 159-hole program has been completed at Diamba Sud since March 2024 (refer to Fortuna news release dated March 11, 2024).

Results from this program will be incorporated into the ongoing project development work, with the encouraging results from Western Splay and Kassasoko expected to contribute toward growing the project portfolio and resource base, while also improving confidence in the regional geological understanding. With the tempo of drilling planned to slow across the forthcoming rainy season, the exploration team will continue to review and fine-tune the geological controls on mineralization.

Figure 1: Diamba Sud Gold Project location plan

Karakara Prospect

Infill and extension drilling at Karakara continued to define additional mineralization beyond the historic pit design, while also providing confirmatory data to help validate previous geological interpretations.

Karakara drilling highlights include:

An updated interpretation supported by further drilling will take place during the third quarter of 2024 to further refine the controls on mineralization, the association with the nearby Area D and the Moungoundi to Southern Arc prospects (refer to Figure 2).

Figure 2: Karakara cross-section showing select results - looking north

Kassasoko Prospect

Drilling at Kassasoko, located approximately 1-kilometer to the southeast of Western Splay, was successful in intersecting several broad zones of mineralization. Drilling highlights include:

In comparison to mineralization elsewhere at Diamba Sud, mineralization at Kassasoko is hosted within a granitic unit and in close proximity to a series of dioritic intrusives (refer to Figure 3). Exploration work is continuing.

Figure 3: Kassasoko cross-section showing select results - looking northeast

Western Splay drilling highlights include:

Drilling continues, extending further to the south to test below an active artisanal area, with the objective of increasing the prospect footprint, as well as improving the geological interpretation of the wider southern area of Diamba Sud, particularly the relationships between the Moungoundi-Western Splay-Kassasoko-Southern Arc prospects.

Figure 4: Western Splay cross-section showing select results - looking north

Refer to Appendix 1 for full details of the drill holes and assay results for this drill program at the Diamba Sud Gold Project.

Quality Assurance & Quality Control (QA - QC)

All drilling data completed by the Company utilized the following procedures and methodologies. All drilling was carried out under the supervision of the Company's personnel.

All reverse circulation (RC) drilling used a 5.25-inch face sampling pneumatic hammer with samples collected into 60-liter plastic bags. Samples were kept dry by maintaining enough air pressure to exclude groundwater inflow. If water ingress exceeded the air pressure, RC drilling was stopped, and drilling converted to diamond core tails. Once collected, RC samples were riffle split through a three-tier splitter to yield a 12.5% representative sample for submission to the analytical laboratory. The residual 87.5% samples were stored at the drill site until assay results were received and validated. Coarse reject samples for all mineralized samples corresponding to significant intervals are retained and stored on-site at the Company-controlled core yard.

All diamond drilling (DD) drill holes started with HQ sized diameter, before reducing to NQ diameter diamond drill bits on intersecting fresh rock. The core was logged, marked up for sampling using standard lengths of one meter or to a geological boundary. Samples were then cut into equal halves using a diamond saw. One half of the core was left in the original core box and stored in a secure location at the Company core yard at the project site. The other half was sampled, catalogued, and placed into sealed bags and securely stored at the site until shipment.

All RC and DD samples were transported to ALS's preparation laboratory in Kedougou, Senegal before also being transported via commercial courier, to ALS's facility in Ouagadougou, Burkina Faso. Routine gold analysis using a 50-gram charge and fire assay with an atomic absorption finish was completed for all samples. Quality control procedures included the systematic insertion of blanks, duplicates and sample standards into the sample stream. In addition, the ALS laboratory inserted its own quality control samples.

Qualified Person

Paul Weedon, Senior Vice President of Exploration for Fortuna Mining Corp., is a Qualified Person as defined by National Instrument 43-101 being a member of the Australian Institute of Geoscientists (Membership #6001). Mr. Weedon has reviewed and approved the scientific and technical information contained in this news release. Mr. Weedon has verified the data disclosed, including the sampling, analytical and test data underlying the information or opinions contained herein by reviewing geochemical and geological databases and reviewing diamond drill core. There were no limitations to the verification process.

About Fortuna Mining Corp.

Fortuna Mining Corp. is a Canadian precious metals mining company with five operating mines in Argentina, Burkina Faso, Côte d'Ivoire, Mexico, and Peru. Sustainability is integral to all our operations and relationships. We produce gold and silver and generate shared value over the long-term for our stakeholders through efficient production, environmental protection, and social responsibility. For more information, please visit our website.

ON BEHALF OF THE BOARD

Jorge A. Ganoza
President, CEO, and Director
Fortuna Mining Corp.

Investor Relations:
Carlos Baca | info@fmcmail.com | fortunamining.com | X | LinkedIn | YouTube

Forward-looking Statements

This news release contains forward-looking statements which constitute "forward-looking information" within the meaning of applicable Canadian securities legislation and "forward-looking statements" within the meaning of the "safe harbor" provisions of the Private Securities Litigation Reform Act of 1995 (collectively, "Forward-looking Statements"). All statements included herein, other than statements of historical fact, are Forward-looking Statements and are subject to a variety of known and unknown risks and uncertainties which could cause actual events or results to differ materially from those reflected in the Forward-looking Statements. The Forward-looking Statements in this news release include, without limitation, statements about the potential of the Diamba Sud Gold Project based on the early success at the Western Splay and Kassasoko prospects, statements relating to the potential to progress the satellite opportunities at the Diamba Sud Gold Project; the proposed plan to update the geological interpretation of certain prospects including the Karakara prospect in the third quarter of 2024; the Company's objectives for the current drilling program at the Diamba Sud Gold Project and expectations regarding additional drilling and exploration programs planned for 2024; the Company's business strategy, plans and outlook; the merit of the Company's mines and mineral properties; mineral resource and reserve estimates; timelines; the future financial or operating performance of the Company; expenditures; approvals and other matters. Often, but not always, these Forward-looking Statements can be identified by the use of words such as "estimated", "potential", "open", "future", "assumed", "projected", "used", "detailed", "has been", "gain", "planned", "reflecting", "will", "containing", "remaining", "to be", or statements that events, "could" or "should" occur or be achieved and similar expressions, including negative variations. Forward-looking Statements involve known and unknown risks, uncertainties and other factors which may cause the actual results, performance or achievements of the Company to be materially different from any results, performance or achievements expressed or implied by the Forward-looking Statements. Such uncertainties and factors include, among others, changes in general economic conditions and financial markets; changes in prices for gold, silver, and other metals; the timing and success of the Company's proposed exploration programs; technological and operational hazards in Fortuna's mining and mine development activities; risks inherent in mineral exploration; fluctuations in prices for energy, labour, materials, supplies and services; fluctuations in currencies; uncertainties inherent in the estimation of mineral reserves, mineral resources, and metal recoveries; the possibility that the appeal in respect of the ruling in favor of Compañia Minera Cuzcatlan S.A. de C.V. reinstating the environmental impact authorization at the San Jose Mine (the "EIA") will be successful; the Company's ability to obtain all necessary permits, licenses and regulatory approvals in a timely manner; governmental and other approvals; political unrest or instability in countries where Fortuna is active; labor relations issues; as well as those factors discussed under "Risk Factors" in the Company's Annual Information Form for the financial year ended December 31, 2023. Although the Company has attempted to identify important factors that could cause actual actions, events or results to differ materially from those described in Forward-looking Statements, there may be other factors that cause actions, events or results to differ from those anticipated, estimated or intended. Forward-looking Statements contained herein are based on the assumptions, beliefs, expectations and opinions of management, including but not limited to expectations regarding the results from the exploration programs conducted at the Company's mineral properties including the Diamba Sud Gold Project; expected trends in mineral prices and currency exchange rates; the accuracy of the Company's information derived from its exploration programs at the Company's mineral properties; current mineral resource and reserve estimates; the presence and continuity of mineralization at the Company's properties; that the Company's activities will be in accordance with the Company's public statements and stated goals; that there will be no material adverse change affecting the Company or its properties; that the appeal filed in the Mexican Collegiate Court challenging the reinstatement of the EIA will be unsuccessful; that all required approvals will be obtained; that there will be no significant disruptions affecting operations and such other assumptions as set out herein. Forward-looking Statements are made as of the date hereof and the Company disclaims any obligation to update any Forward-looking Statements, whether as a result of new information, future events or results or otherwise, except as required by law. There can be no assurance that Forward-looking Statements will prove to be accurate, as actual results and future events could differ materially from those anticipated in such statements. Accordingly, investors should not place undue reliance on Forward-looking Statements.

Cautionary Note to United States Investors Concerning Estimates of Reserves and Resources

Reserve and resource 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 Definition Standards on Mineral Resources and Mineral Reserves. NI 43-101 is a rule developed by the Canadian Securities Administrators that establishes standards for public disclosure by a Canadian company of scientific and technical information concerning mineral projects. Unless otherwise indicated, all mineral reserve and mineral resource estimates contained in the technical disclosure have been prepared in accordance with NI 43-101 and the Canadian Institute of Mining, Metallurgy and Petroleum Definition Standards on Mineral Resources and Reserves. Canadian standards, including NI 43-101, differ significantly from the requirements of the Securities and Exchange Commission, and mineral reserve and resource information included in this news release may not be comparable to similar information disclosed by U.S. companies.

Appendix 1: Diamba Sud Gold Project, Senegal

Explanatory Notes:

A. EOH - End of hole

B. NSI: No significant intercepts

C. ETW: Estimated true width

D. Depths and widths reported to nearest significant decimal place

E. DD: diamond drilling tail | RC: reverse circulation drilling

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