Marathon Gold Files Updated Technical Report for the Valentine Gold Project

TORONTO, April 23, 2021 - Marathon Gold Corp. ("Marathon" or the "Company"; TSX: MOZ) is pleased to report that it has filed an updated technical report in accordance with National Instrument 43-101 - Standards of Disclosure for Mineral Projects for the Valentine Gold Project in central Newfoundland, available on SEDAR (www.sedar.com).

The technical report is entitled "N.I. 43-101 Technical Report & Feasibility Study on the Valentine Gold Project, Newfoundland and Labrador, Canada" and has been prepared by Ausenco Engineering Canada Inc. with an effective date of April 15, 2021. The report contains updates to the Mineral Resource Estimate of the Project effective November 20, 2020 (Marathon, Leprechaun, Sprite and Victory deposits) and April 15, 2021 (Berry deposit), both prepared by John T. Boyd Company.

The Valentine Gold Project Feasibility Study ("FS") supports an open pit mining operation with low initial capital cost and high rate of return over a 13-year mine life (see Marathon news release dated March 29, 2021). Highlights include:

• After-tax Internal Rate of Return of 31.5% and Net Present Value at a 5% discount rate ("NPV_5%") of $600M (US$450M) at US$1,500/oz gold, increasing to 42.2% and $868M (US$651M) at US$1,750/oz gold;
• Initial capital cost ("Capex") of $305M (US$229M) yielding a favourable after-tax NPV_5%/Capex ratio of 2.0. Total life-of-mine ("LOM") capital of $662M (US$496M);
• After-tax payback of 1.9 years;
• 22 months construction and commissioning schedule assuming construction start in January 2022. First gold pour in October 2023;
• Average gold production of 173,000 oz/year and $119M of annual average free cash flow ("FCF") between 2024 and 2033 from the processing of high-grade mill feed, and 56,000 oz/year and $31M FCF/year between 2034 and 2036 from the processing of low-grade stockpiles;
• LOM Total Cash Costs of US$704/oz and All-In Sustaining Costs of US$833/oz;
• Mill capacity of 6,800 tpd (2.5 Mtpa) based on gravity-leaching, expanding to 11,000 tpd (4.0 Mtpa) in Year 4 based on gravity-flotation-leaching. LOM average gold recovery of 94.2% for total LOM recovered gold production of 1.93 Moz; and
• Proven and Probable Mineral Reserves of 2.05 Moz (47.06 Mt at 1.36 g/t Au);

Following recent completion of the maiden mineral resource estimate for the Berry deposit (see Marathon news release dated April 21, 2021), total mineral resources at the Project now stand at:

• Measured and Indicated Mineral Resources of 3.14 Moz (56.66 Mt at 1.72 g/t Au); and
• Inferred Mineral Resources now stand at 1.64 Moz (29.59 Mt at 1.72 g/t Au).

The FS was completed by Ausenco Engineering Canada Inc. as Lead Consultant. Moose Mountain Technical Services acted as Mining Consultant, APEX Geoscience Ltd. as Geological Consultant, Golder Associates Ltd. as Tailings Consultant, Stantec Consulting Ltd. as Site Water Management and Environmental Consultant, and GEMTEC Consulting Engineers and Scientists Limited as Geotechnical Consultant. The Valentine Gold Project Mineral Resource Estimate was prepared by John T. Boyd Company. The Mineral Reserve Estimate was prepared by Moose Mountain Technical Services.

Qualified Persons

Disclosure of a scientific or technical nature in this news release has been approved by Mr. Tim Williams, FAusIMM, Chief Operating Officer of Marathon, Mr. Paolo Toscano, P.Eng. (Ont.), Vice President, Projects for Marathon, and Mr. James Powell, P.Eng. (NL), Vice President, Regulatory and Government Affairs for Marathon. Mr. Williams, Mr. Toscano and Mr. Powell are qualified persons under National Instrument ("NI") 43-101.

About Marathon

Marathon (TSX:MOZ) is a Toronto based gold company advancing its 100%-owned Valentine Gold Project located in the central region of Newfoundland and Labrador, one of the top mining jurisdictions in the world. The Project comprises a series of five mineralized deposits along a 20-kilometre system. An April 2021 Feasibility Study outlined an open pit mining and conventional milling operation over a thirteen-year mine life with a 31.5% after-tax rate of return. The Project has estimated Proven Mineral Reserves of 1.40 Moz (29.68 Mt at 1.46 g/t) and Probable Mineral Reserves of 0.65 Moz (17.38 Mt at 1.17 g/t). Total Measured Mineral Resources (inclusive of the Mineral Reserves) comprise 1.92 Moz (32.59 Mt at 1.83 g/t) with Indicated Mineral Resources (inclusive of the Mineral Reserves) of 1.22 Moz (24.07 Mt at 1.57 g/t). Additional Inferred Mineral Resources are 1.64 Moz (29.59 Mt at 1.72 g/t Au). Please see Marathon's Annual Information Form for the year ended December 31, 2020 and other filings made with Canadian securities regulatory authorities and available at www.sedar.com for further details and assumptions relating to the Valentine Gold Project.

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To find out more information on Marathon Gold Corp. and the Valentine Gold Project, please visit www.marathon-gold.com.

Cautionary Statement Regarding Forward-Looking Information

Certain information contained in this news release, constitutes forward-looking information within the meaning of Canadian 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 Marathon expects to occur are forward-looking statements. Forward-looking statements include statements that are predictive in nature, depend upon or refer to future events or conditions, or include words such as "expects", "anticipates", "plans", "believes", "estimates", "considers", "intends", "targets", or negative versions thereof and other similar expressions, or future or conditional verbs such as "may", "will", "should", "would" and "could". We provide forward-looking statements for the purpose of conveying information about our current expectations and plans relating to the future, and readers are cautioned that such statements may not be appropriate for other purposes. More particularly and without restriction, this news release contains forward-looking statements and information about Marathon's intention to complete the Offering and the timing thereof, economic analyses for the Valentine Gold Project, capital and operating costs, processing and recovery estimates and strategies, future exploration and mine plans, objectives and expectations and corporate planning of Marathon, future feasibility studies and environmental impact statements and the timetable for completion and content thereof and statements as to management's expectations with respect to, among other things, the matters and activities contemplated in this news release.

Forward-looking statements involve known and unknown risks, uncertainties and assumptions and accordingly, actual results and future events could differ materially from those expressed or implied in such statements. You are hence cautioned not to place undue reliance on forward-looking statements. 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.

By its nature, this information is subject to inherent risks and uncertainties that may be general or specific and which give rise to the possibility that expectations, forecasts, predictions, projections or conclusions will not prove to be accurate, that assumptions may not be correct and that objectives, strategic goals and priorities will not be achieved. Factors that could cause future results or events to differ materially from current expectations expressed or implied by the forward-looking statements include receipt of all necessary regulatory approvals, completion of all conditions to closing of the Offering, availability of financing to fund Marathon's exploration and development activities, the ability of the current exploration program to identify and expand mineral resources, operational risks in exploration and development for gold, Marathon's ability to realize the pre-feasibility study, delays or changes in plans with respect to exploration or development projects or capital expenditures, uncertainty as to calculation of mineral resources, changes in commodity and power prices, changes in interest and currency exchange rates, the ability to attract and retain qualified personnel, inaccurate geological and metallurgical assumptions (including with respect to the size, grade and recoverability of mineral resources), changes in development or mining plans due to changes in logistical, technical or other factors, title defects, government approvals and permits, cost escalation, changes in general economic conditions or conditions in the financial markets, environmental regulation, operating hazards and risks, delays, taxation rules, competition, public health crises such as the COVID-19 pandemic and other uninsurable risks, liquidity risk, share price volatility, dilution and future sales of common shares, aboriginal claims and consultation, cybersecurity threats, climate change, delays and other risks described in Marathon's documents filed with Canadian securities regulatory authorities.

You can find further information with respect to these and other risks in Marathon's Amended and Restated Annual Information Form for the year ended December 31, 2019 and other filings made with Canadian securities regulatory authorities available at www.sedar.com. Other than as specifically required by law, Marathon undertakes no obligation to update any forward-looking statement to reflect events or circumstances after the date on which such statement is made, or to reflect the occurrence of unanticipated events, whether as a result of new information, future events or results otherwise.