Monumental Minerals Corp. Provides Update Following Laguna Blanca Cesium-lithium Brine Project Site Visit

VANCOUVER, April 25, 2022 - Monumental Minerals Corp. ("Monumental" or the "Company") (TSXV: MNRL) (FSE: BE5) (OTCQB: MNMRF) is pleased to provide an update on management's recent visit to its Salar De Laguna Blanca Cesium-Lithium Brine Salar Project (the "Laguna Project") (see Monumental Minerals news release dated April 21, 2022).

Members of Monumental's management team and board of directors (Fig. 1) visited a portfolio of Lithium Chile assets, including the Laguna Project, with representatives of Lithium Chile Inc. (TSXV: LITH). The Laguna Project was accessed by travelling 80 kilometres west from the town of San Pedro de Atacama via the paved road 27CH to the north end of Salar de Aguas Calientes, then along a truck - accessible trail heading north to the property (Fig. 2).

The long axis of the Laguna Blanca Salar is controlled by a major northwest-southeast trending fault that was observed during the site visit. This fault is interpreted to provide a structural conduit promoting brine interaction with felsic volcanics, including thick sequences of ignimbrites (volcanic ash), from which lithium and cesium were leached, transported, and subsequently concentrated in brines and sediments within the Laguna Blanca Salar (Fig. 3). Other salars in the area, including Salar De Helados (100% owned by Lithium Chile) were also visited by the Company during the site visit that related to this same fault structure. Brine-saturated and unsaturated sediment samples collected by Lithium Chile from the Laguna Project returned values of 0.145% and 0.069% lithium and cesium, respectively, and the highest concentrations form a trend parallel with the NW-SE structural trend (Fig. 4a and b). Brine samples collected from shallow augered holes within the brine pool (approximately 1.5 m depth) returned values of 1,230 mg/L Li; and 40 mg/L Cs (see Monumental Minerals' news release dated March 9, 2022).

While on-site at the Laguna Project, the Company examined ease of access, potential seasonal and weather constraints, and proximity to infrastructure in order to plan an exploration work program. The work program going forward will also be coordinated with Lithium Chile, local communities, and stakeholders.

In addition, Monumental's management met with Summit Nanotech ("Summit") in Antofagasta, Chile to discuss their direct lithium extraction (DLE) technology, including their pilot plant. A bulk brine sample from the Laguna Project will be submitted to Summit for preliminary testing using their pilot plant upon completion of the Company's first borehole at the Laguna Project. Summit is developing 1000 m³/day modular units designed to increase yield, reduce climate pollution, minimize the use of chemicals and freshwater, and reduce waste by 90% compared to traditional evaporation lithium extraction methods.

Dr. Jamil Sader, Monumental's CEO and Director comments:

"Seeing the Laguna Blanca Project site gave us a true appreciation of the size, scope, and quality of this important asset within the prolific Lithium Triangle. We appreciate the deep technical, social, and environmental knowledge that Lithium Chile contributes and we are thrilled to be partnered with them on this Project."

The company would also like to congratulate Lithium Chile on the recent 19.9% purchase investment by Chengixin Lithium Corp., a publicly listed company in China with a market capitalization of 45.6 billion yuan (CAD $9 billion). Chengxin is primarily engaged in the new energy materials business including production from spodumene and brines as well as manufacturing of lithium products including lithium hydroxide and lithium carbonate. Following the recent transaction of Laguna Blanca (subject to TSX approval), Lithium Chile will become Monumental Minerals largest shareholder, owning 9.9% of the company.

Maximilian Sali, Founder and Director of the Company comments:

"Following a tremendous site visit with Lithium Chile I want thank Steve, Al and Terrance for the invaluable experience that Monumental has gained. We look forward to working with them on Laguna Blanca as a valued partner."

The Laguna Project is an early exploration stage project located within the prolific lithium triangle, a zone within the central Andes high desert that includes Chile, Argentina, and Bolivia. This zone is estimated to contain more than half of the world's lithium supply beneath the many salt flats, also known as salars, that are common to the region. The Laguna Blanca property consists of 23 exploration concessions totaling 5,200 hectares, 100% owned by Lithium Chile through its wholly-owned Chilean subsidiary Minera Kairos Chile Limitada ("Minera Kairos"). The Laguna Project is within 120 km of Salar de Atacama, the largest producing salar in the world, which is operated by SQM and Albemarle.

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.

About Monumental Minerals Corp.
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 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

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 plan to submit a bulk brine sample from the Laguna Project to Summit for testing, potential plans for the Company's projects, 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.

SOURCE Monumental Minerals Corp.