Lighthouse Gold signs LOI for Mariwa-Sardine Hill in Guyana

Vancouver, British Columbia – June 15, 2026 – TheNewswire – Lighthouse Gold Corp. (CSE:LGHT) (“ Lighthouse ” or the “ Company ”) is pleased to announce that it has entered into a binding letter of intent (the “ LOI ”) to acquire a 100% interest in the Mariwa/Sardine Hill - Lower Cuyuni Gold Property (the “ Property ”), located within the highly prospective Oko Gold District in Guyana, South America. The acquisition will represent a strategic expansion of Lighthouse’s Guyana-focused exploration portfolio and provides the Company with exposure to a historically productive gold district situated within the prolific Guiana Shield, one of the world’s premier gold-bearing geological provinces. Key Highlights The Property is comprised of three (3) contiguous Mining Permits Medium Scale (MPMS) which provide the holder with the right to explore and develop mineral resources within the permitted areas, subject to applicable regulatory approvals.  The Property totalling approximately 3,240 acres, is located in the Cuyuni Mining District No. 4, northwest Guyana and is part of a broader mineralized corridor where artisanal gold miners have been actively mining for more than 100 years and a belt that is host to several significant gold deposits.  Historical exploration spanning more than three decades on the Property has identified a structurally controlled gold system confirmed by shallow drilling across all three blocks with significant exploration upside remaining.   Highlights from historical work include trench result of 17.40 grams per tonne (“ g/t ”) Au from the central zone and two diamond drill holes reporting 113.5 meters at 1.39 g/t Au from near surface and a deeper intercept of 93 meters at 0.69 g/t Au (inclined holes and true widths unknown).  Additionally, geological, geophysical and geochemical data outline anomalies and targets both in saprolite and hard rock that haven’t been tested to date by drilling.  The Company cautions that these historical results have not been independently verified by Lighthouse Gold and should not be relied upon as indicative of future exploration success.

The Property is located within the broader Guiana Shield gold district of Guyana, an area that has recently attracted significant industry attention following the announced combination of G Mining Ventures Corp. and G2 Goldfields Inc. to consolidate the Oko     gold district. The Property is approximately 31 kilometres from Oko, 8 kilometers from Wariri, 18 kilometers from Groete Creek and occurs within the same highly prospective regional geological terrain that continues to attract exploration and development activity from both junior and major mining companies. The proximity of the Property to other mineral deposits or occurrences does not necessarily indicate that the Property hosts similar mineralization or that economic mineralization will be discovered on the Property.   “The Mariwa/Sardine Hill - Lower Cuyuni acquisition provides Lighthouse with a strategic foothold in one of Guyana’s emerging gold districts,” stated Will Rascan, Interim CEO of Lighthouse Gold. “Recent consolidation activity in the Cuyuni - Oko region has highlighted the value of district-scale land positions within the Guiana Shield.

We believe the Property hosts favourable geological characteristics for gold mineralization and offers exploration upside through the application of modern exploration techniques and the reinterpretation of historical datasets.”     Rascan further states, “Management believes the Mariwa/Sardine Hill - Lower Cuyuni Property is well-positioned given its location along a regional mineralized corridor that hosts numerous historical gold occurrences, active mining operations and early and advanced-stage exploration projects. The Company views the acquisition as an opportunity to leverage historical exploration success while applying modern geological interpretation and targeting techniques across a consolidated land position.” Historical Exploration Highlights The Sardine Hill - Lower Cuyuni district hosts extensive historical exploration data, including airborne geophysics, auger geochemistry, trenching and diamond drilling programs.   Historical exploration programs have been conducted by multiple operators since the early 1990s, including International Roraima Gold Corp (1994–1997), Newmont (2004), and Guyana Frontier Mining Corp (2011). The 1997 Roraima Summary Report established the Lower Cuyuni prospect as a drill-confirmed gold zone with consistent mineralization across all three blocks, forming a coherent N-S corridor approximately 1,500 metres in strike length.

Block 1 is the most advanced of the three blocks in terms of the historic data. Diamond drilling confirmed gold mineralization grading 1.39 g/t gold over 113.5 metres (inclined hole, and true width of mineralized intersection unknown), with the hole ending in saprolite, highlighting the deep weathering in this area which in places extends greater than 100 meters vertically according to historical literature. The mineralised body remains open along strike and at depth.

In addition, several auger drilling results showed gold up to 2.99 g/t gold from shallow depths, within 6 meters of surface. Block 3 hosts the highest individual gold result in the dataset. Trenching returned 17.40 g/t gold over 1 metre within mica-chlorite schist of the Blue Mountain Formation, within an interpreted high-grade structural zone linking the northern and southern anomalies.

Multiple electromagnetic conductors cross this block which have yet to be drill-tested. Block 2 is the least explored block. Power auger sampling returned values including 1.95 g/t gold, with the main anomaly remaining open to the west.

Regional stream sediment sampling by the Guyana Geology and Mines Commission returned 0.033 g/t gold (BLEG) in the Mariwa River drainage through this block. Historical reports indicate that much of the exploration completed within the district focused primarily on shallow oxide mineralization, while the underlying fresh rock zones remain largely untested. Historic, independent geophysical surveys highlight the structural complexity of the district and the potential to define additional targets beyond the previously drilled zones.

The Company cautions that these historical results have not been independently verified by Lighthouse Gold and should not be relied upon as indicative of future exploration success. The Company considers the historical information relevant as it assists in defining exploration targets and supports the presence of a large-scale mineralized gold system within the district. Historical data is currently being reviewed and compiled by the Company’s technical team.

Initial Exploration Strategy Over the term of the Definitive Agreement (defined herein), Lighthouse intends to undertake a comprehensive technical review of the district, including:   compilation and digitization of historical exploration data;   reconstruction of historical drill hole and geophysical databases;   detailed geological and structural interpretation;   evaluation of regional exploration targets;   actively pursuing additional strategic land acquisitions to build a district-scale exploration portfolio; and  prioritization of targets for follow-up field programs, trenching and drilling.   Transaction Terms As contemplated in the LOI, the LOI will be superseded and replaced in its entirety by the terms and conditions of a definitive agreement between the parties (the “Definitive Agreement”), which will reflect Lighthouse being granted the right to acquire a 100% interest in the Property through a combination of cash payments and common share issuances. The consideration payable under the Definitive Agreement will consists of: US$100,000 non-refundable cash deposit payable within five business days of execution of the LOI;   US$150,000 cash payment payable within five business days of execution of the Definitive Agreement;   issuance of 35,000,000 common shares of Lighthouse Gold within five business days of execution of the Definitive Agreement; and   annual cash payments of US$200,000 on or before each of the Definitive Agreement anniversaries over four years, totaling US$800,000.   Upon completion of the required payments and the share issuance, Lighthouse will earn a 100% interest in the Property, subject to a 1.0% Net Smelter Return Royalty (“ NSR ”) in favour of the vendor. Lighthouse may repurchase the NSR at any time for US$4,000,000.  In addition to the Property itself, the LOI includes a 10-kilometre area of interest provision, which will provide Lighthouse with the right to acquire certain additional mineral rights that may be staked or acquired by the vendor within the surrounding district during the term of the agreement.   The transaction remains subject to completion of satisfactory due diligence, execution of a Definitive Agreement, regulatory approvals and acceptance by the Canadian Securities Exchange.

The scientific and technical information contained in this news release has been reviewed and approved by Gregory Smith, P.Geo., a director of the Company, and a Qualified Person as defined by National Instrument 43-101 – Standards of Disclosure for Mineral Projects. The Qualified Person has reviewed available historical technical reports and data sources and considers the information to be relevant for exploration planning purposes, although certain historical data has not been independently verified. About Lighthouse Gold Lighthouse Gold is a Canadian gold exploration company focused on advancing high-potential exploration and mining assets in Guyana.

ON BEHALF OF THE BOARD OF DIRECTORS Geoff Balderson, CFO & Director   For further information regarding Lighthouse, please contact. Will Rascan Interim CEO will@lighthousegold.com   Cautionary Note Regarding Forward-Looking Statements This news release contains forward-looking statements within the meaning of applicable securities laws. Forward-looking statements are often identified by words such as “expects,” “anticipates,” “believes,” “intends,” “plans,” “may,” “will,” “should,” “potential,” “proposed,” and similar expressions, or statements that certain events or conditions “will” or “may” occur.

These statements relate to future events or future performance and include, without limitation, statements regarding the proposed acquisition of the Property, completion of the Definitive Agreement, the Company’s exploration plans and strategies, the potential for mineralization on the Property, and other business objectives. Forward-looking statements are based on the reasonable assumptions, estimates, expectations, analyses, and opinions of management made in light of its experience and perception of trends, current conditions, and expected developments, as well as other factors that management believes to be relevant and reasonable in the circumstances at the date such statements are made. Although the Company believes that the assumptions and expectations reflected in the forward-looking statements are reasonable, there can be no assurance that such statements will prove to be accurate.

Forward-looking statements involve known and unknown risks, uncertainties, and other factors that may cause actual results, performance, or achievements to differ materially from those expressed or implied by such forward-looking statements. Such risks and uncertainties include, but are not limited to: the parties’ inability to complete the transaction on the terms contemplated or at all; failure to satisfy conditions precedent to the completion of the transaction, including regulatory approvals; risks related to the reliance on historical exploration data that has not been independently verified; uncertainties inherent in the estimation of mineral resources; risks related to exploration and development of mineral properties; title and permitting risks; changes in commodity prices; general business, economic, competitive, political, and social uncertainties; and other risks and uncertainties described in the Company’s public filings. Readers are cautioned not to place undue reliance on forward-looking statements.

The Company undertakes no obligation to update or revise any forward-looking statements, whether as a result of new information, future events, or otherwise, except as required by applicable securities laws. The Canadian Securities Exchange has not in any way passed upon the merits of the transaction and has neither approved nor disapproved the contents of this press release.      Copyright (c) 2026 TheNewswire - All rights reserved. TheNewsWire June 15, 2026 - 5:00 AM PDT News by QuoteMedia www.quotemedia.com