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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, Mexico

Drill Results Sampling & Geoscience Results

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, MEXICO

News Release - Vancouver, British Columbia – June 15 , 2022: Monumental Minerals Corp.

(“Monumental” or the “Company”) (TSX-V: MNRL; FSE: BE5; OTC: MNMRF) is pleased to announce

the results of 21 select rock grab samples collected from its Jemi Heavy Rare Earth Element (HREE)

Project, located in Coahuila, Mexico, about 40 km south of the Texas, USA border.

The Jemi rock samples have retu rned some of the highest HREE grades sampled to date and serve to

confirm and reinforce the Compan y’s understanding of mineralization controls at Jemi. Significa ntly, 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 TREO 1 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.

Table 1. Rare earth element and base metal assay results from select samples collected during the April 2022 Jemi site visit.

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

1 Total Rare Earth Oxides (TREO) includes: La2O3, Ce2O3, Pr2O3, Nd2O3, Sm2O3, Eu2O3, Gd2O3, Tb2O3, Dy2O3, Ho2O3, Er2O3,

Tm2O3, Yb2O3, Lu2O3, Y2O3.

2 Heavy Rare Earth Oxides (HREO) includes: Eu2O3, Gd2O3, Tb2O3, Dy2O3, Ho2O3, Er2O3, Tm2O3, Yb2O3, Lu2O3, Y2O3.

Sample ID TREO

(%)

HREO

(%)

Dy2O3

(ppm)

Tb2O3

(ppm)

Nd2O3

(ppm)

Pr2O3

(ppm)

Ho2O3

(ppm)

Lu2O3

(ppm)

Y2O3

(ppm)

Ta2O5

(ppm)

Nb2O5

(ppm)

ZrO2

(ppm)

Zn

(%)

Pb

(%)

Rock Type

22KRP018 0.54 0.26 240 36 657 157 56 25 1708 306 1788 >13500 0.02 0.008 Peralkaline

22KRP004 0.42 0.16 155 23 491 145 34 12 1060 170 2561 >13500 0.08 0.017 Peralkaline

22KRP002 0.29 0.08 83 12 341 104 19 10 504 69 920 9496 0.04 0.009 Peralkaline

22KRP006 0.18 0.08 72 11 160 43 16 7 504 49 740 >13500 0.02 0.014 Peralkaline

22-JSP-03 0.16 0.05 43 7 218 65 9 4 300 140 2038 >13500 0.08 0.099 Metaluminous

22-JSP-02 0.07 0.04 33 5 68 17 8 6 229 25 429 7389 0.02 0.012 Peralkaline

22KRP020 0.11 0.04 32 5 131 37 8 5 241 67 798 9428 0.01 0.002 Peralkaline

22KRP003 0.12 0.03 30 4 143 45 7 5 192 24 455 6592 0.02 0.003 Peralkaline

22KRP001 0.19 0.03 30 5 260 81 6 5 177 26 508 4728 0.05 0.011 Peralkaline

22KRP009 - - - - - - - - - - - - 13.5 6.82 -

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.

Figure 1. Location of samples collected during the April 2022 Jemi site visit, showing values of the HREE

dysprosium and rock types.

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.

Qualified Person

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) progra m 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.

About Monumental Minerals Corp.

Monumental Minerals Corp. is a mineral exploration company focused on the acquisition, exploration, and

development of mineral res ource 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

Contact Information:

Email: [email protected]

Or

Email: [email protected]

Neither the TSX Venture Exchange nor its Regulation Services Provider (as that term is defined in the

policies of the TSX Venture Exchange) accepts responsibility for the adequacy or accuracy of this news

release.

Forward Looking Information

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 Compa ny 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.