Monumental Minerals Corp. Samples 0.54% Total Rare Earth Oxide And 0.26% Heavy Rare Earth Oxide Confirming Significant Rare Earth Grades At Jemi Heavy Rare Earth Element Project

The Jemi rock samples have returned some of the highest HREE grades sampled to date and serve to confirm and reinforce the Company's understanding of mineralization controls at Jemi. Significantly, the rock sample results released today also establish the HREE potential of multiple visually distinct lithologies, which opens the potential for the discovery of previously unrecognized new zones of HREE mineralization.

Of the 21 select rock grab samples, a total of seven returned values greater than 0.15% total rare earth oxide (TREO¹), including three samples that returned values greater than 0.25% TREO¹ and up to 0.54% TREO¹ (22KRP018). Samples with the highest TREO¹ values also returned the highest heavy rare earth oxide (HREO²) values - 0.26% and 0.16% for samples 22KRP018 (Veladora North area) and 22KRP004 (JEMI Dyke area), respectively (Table 1, Fig. 1). The assay results confirm that samples with the highest REE content are those rocks that are classified as peralkaline (sodium plus potassium concentrations are greater than aluminum concentrations). In HREE mineral systems, rocks must be peralkaline in order for the crystallization of HREE bearing silicate minerals like eudialyte to occur. Peralkaline rocks are defined along the 8 km strike length determined by airborne radiometrics (see Monumental Minerals Press Release May 3, 2022). In addition, a single rock grab sample collected in the eastern claim area returned values of 13.5% zinc and 6.82% lead (22KRP009, Table 1, Fig. 1) and is classified as carbonate replacement-style mineralization.

Jamil Sader, Monumental's CEO and Director comments:

"We are excited by the significance of the rock grab sample results released today, in that they confirm the presence of economically significant HREE values and the right rock type. They also confirm the highest HREE values returned to date at Jemi, and establish the potential for multiple underexplored new zones of mineralization not previously recognized. We look forward to commencing our expanded program of geologic mapping, surface geochemical sampling and ground radiometric geophysical surveying in the coming weeks to define targets for diamond drill testing as early as late Q3."

Heavy rare earth target areas within the Jemi Project are indicated by positive airborne radiometrics that define two parallel 8 km arcuate anomalies occurring along the southwest margin of the Sierra La Vasca intrusive complex. At Jemi, radiometric anomalies are spatially associated with HREE mineral occurrences. These occurrences are comprised of eudialyte bands within alkaline dykes, veins, and disseminations that have been emplaced into host carbonate rocks at both the Project's Veladora North and JEMI Dyke areas.

The Jemi Project hosts numerous REE occurrences containing potentially economic concentrations of the high value magnetic REEs including the HREEs dysprosium (Dy) and terbium (Tb), and the light rare earth elements (LREE) neodymium (Nd), praseodymium (Pr). The Project also contains associated tantalum (Ta), niobium (Nb), and zirconium (Zr). Jemi sits within the North American Alkaline Igneous Belt, an under explored north-south trend over 3000 km long of alkaline igneous rocks and carbonatites that are host to numerous REE, gold and other critical element deposits.

The REE mineralization discovered to date at Jemi exhibits characteristics and mineralogy consistent with peralkaline intrusion related deposits, which represent an important potentially economic style for the highest value HREE. Deposits of this type are being explored and prepared for development in Australia, Europe, and North America.

The scientific and technical information contained in this news release has been reviewed and approved by Kristopher J. Raffle, P.Geo. (BC) Principal and Consultant of APEX Geoscience Ltd. of Edmonton, AB, a Director of the Company and a "Qualified Person" as defined in National Instrument 43-101 - Standards of Disclosure for Mineral Projects. Mr. Raffle verified the data disclosed which includes a review of the sampling, analytical and test data underlying the information and opinions contained therein.

The analytical work reported on herein was performed by ALS Canada Ltd. (ALS) at Hermosillo, Mexico (sample preparation) and Vancouver, B.C. (ICP-MS fusion). ALS is an ISO-IEC 17025:2017 and ISO 9001:2015 accredited geoanalytical laboratory and is independent of Monumental Minerals and the QP. Rock samples were subject to crushing at a minimum of 70% passing 2 mm, followed by pulverizing of a 250-gram split to 85% passing 75 microns. A 0.1-gram sample pulp was then subject to multi-element ICP-MS analysis via lithium-borate fusion to determine individual REE content (ME-MS81). Monumental Minerals quality assurance/quality control (QA/QC) program for field rock samples includes the insertion of certified reference standards into the sample sequence to confirm the accuracy of the reported results. Monumental Minerals detected no significant QA/QC issues during review of the data, and is not aware of any sampling, or other factors that could materially affect the accuracy of the results.

Monumental Minerals Corp. is a mineral exploration company focused on the acquisition, exploration, and development of mineral resource properties in the critical and electric metals sector. The Company's flagship asset is the Jemi HREE project located in Coahuila, Mexico near the Texas, USA border which the Company has an option to acquire 100% of the 3,650-hectare project. The Company has an option to acquire a 75% interest and title to the Laguna cesium-lithium brine project located in Chile. The Company has an option to acquire a 100% interest and title to the Weyman property located in the Kamloops and Nicola Mining Divisions and in the Thompson Nicola Regional District, British Columbia.

On behalf of the Board of Directors,

/s/ "Jamil Sader"
Jamil Sader, Chief Executive Officer and Director

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This news release contains "forward-looking information or statements" within the meaning of applicable securities laws, which may include, without limitation, the potential plans for the Company's projects including an expanded program of geological mapping, surface geochemical sampling and ground radiometric geophysical surveying to define targets for drill testing on the Jemi project and the expected timing and completion of these work programs, other statements relating to the technical, financial and business prospects of the Company, its projects and other matters. All statements in this news release, other than statements of historical facts, that address events or developments that the Company expects to occur, are forward-looking statements. Although the Company believes the expectations expressed in such forward-looking statements are based on reasonable assumptions, such statements are not guarantees of future performance and actual results may differ materially from those in the forward-looking statements. Such statements are based on numerous assumptions regarding present and future business strategies and the environment in which the Company will operate in the future, including the price of metals, the ability to achieve its goals, that general business and economic conditions will not change in a material adverse manner and that financing will be available if and when needed and on reasonable terms. Such forward-looking information reflects the Company's views with respect to future events and is subject to risks, uncertainties and assumptions, including the risks and uncertainties relating to the interpretation of exploration results, risks related to the inherent uncertainty of exploration and cost estimates and the potential for unexpected costs and expenses and those other risks filed under the Company's profile on SEDAR at www.sedar.com. While such estimates and assumptions are considered reasonable by the management of the Company, they are inherently subject to significant business, economic, competitive and regulatory uncertainties and risks. Factors that could cause actual results to differ materially from those in forward looking statements include, but are not limited to, continued availability of capital and financing and general economic, market or business conditions, failure to secure personnel and equipment for work programs, adverse weather and climate conditions, risks relating to unanticipated operational difficulties (including failure of equipment or processes to operate in accordance with specifications or expectations, cost escalation, unavailability of materials and equipment, government action or delays in the receipt of government approvals, industrial disturbances or other job action, and unanticipated events related to health, safety and environmental matters), risks relating to inaccurate geological assumptions, failure to maintain all necessary government permits, approvals and authorizations, fluctuation in exchange rates, the impact of Covid-19 or other viruses and diseases on the Company's ability to operate, an inability to predict and counteract the effects of COVID-19 on the business of the Company, including but not limited to, the effects of COVID-19 on the price of commodities, capital market conditions, restriction on labour and international travel and supply chains, decrease in the price of rare earth elements, lithium, cesium and other metals, loss of key employees, consultants, or directors, failure to maintain community acceptance, increase in costs, litigation, and failure of counterparties to perform their contractual obligations. The Company does not undertake to update forward-looking statements or forward-looking information, except as required by law.