North Shore Advances Rio Puerco Towards Drilling

VANCOUVER, BC / ACCESS Newswire / October 29, 2025 / North Shore Uranium Ltd. (TSXV:NSU) ("North Shore" or the "Company") is pleased to provide an update on its Rio Puerco uranium project in the Grants Uranium District of northwestern New Mexico ("Rio Puerco" or the "Project").

As previously announced, a historical resource estimate of 6.0 million tonnes at an average grade of 0.09% eU₃O₈ for 11.4 million pounds of U₃O₈ was reported for Rio Puerco in 2009 (the "Historical Resource"). The Historical Resource was based on drill data gathered by Kerr McGee Corporation ("Kerr McGee") in the 1960s and 1970s ^[1][2][3].

Through a systematic analysis of historical data, the Company has developed a preliminary model of the interpreted uranium mineralization at Rio Puerco. The analysis highlighted some compelling findings, including:

• There is the potential to expand the reported uranium mineralization beyond the Historical Resource located in section 18, but within the claim blocks controlled by the Company,

• Kerr-McGee made a substantial commitment to Rio Puerco in the 1960 and 1970s, producing valuable data including information from over 1,000 drill holes. The Company has obtained sufficient comfort that historical work at Rio Puerco was done to a high standard and can be used as a foundation to efficiently and effectively plan for future drill programs, and

• the historical data supports the potential for in-situ recovery ("ISR") mining, the lowest cost method for producing uranium.

North Shore is now planning for an H1 2026 drill program, which is expected to be comprised of several sections, or "fences" of drill holes designed to verify interpreted zones of uranium mineralization within the Historical Resource and confirm uranium mineralization footprint outside of the Historical Resource area. The Company has begun the permit application process with the Bureau of Land Management ("BLM") and the state of New Mexico.

Brooke Clements, President and CEO of North Shore stated: "North Shore's Rio Puerco project in New Mexico, USA, hosts a significant historical uranium resource with excellent upside, including the potential for confirming uranium mineralization outside of the known Historical Resource in section 18. We look forward to future drill programs at Rio Puerco which will be designed to both confirm and expand upon the known uranium minerialization. The USA has recently expressed a strong desire to stimulate domestic uranium production and we are well-positioned to take advantage of that enthusiasm. Just yesterday, Cameco Corp. and Brookfield Asset Management announced a strategic partnership with the US government that would support nuclear reactor development in the USA and elsewhere."

RIO PUERCO URANIUM MINERALIZATION
A preliminary 3-D model of the interpreted uranium mineralization in Section 18 has been prepared by North Shore based primarily on data from Kerr McGee drilling summarized in a 1975 consultant's report^[4], and geologic cross-sections in the 2011 technical report². The 3-D model is being used to facilitate planning for the Company's first drill program, which will be aimed at verifying portions of the Historical Resource at Rio Puerco and expanding beyond the Historical Resource.

As a general illustration of the interpreted stratigraphy and uranium mineralization at Rio Puerco, Cross-section 18-005 is presented below in Figure 2. The following is a selection of interpreted uranium mineralization intersections for historical drill holes in Cross-section 18-005:

• 18-25

  • 3.2 m @ 0.14% eU₃O₈ from 177.4 m

  • 1.4 m @ 0.22% eU₃O₈ from 182.7 m

• 18-25C (Core hole drilled near rotary hole described above)

  • 3.4 m @ 0.3% eU₃O₈ from 181.5 m

• 18-727

  • 0.5 m @ 0.13% eU₃O₈ from 177.4 m

  • 4.3 m @ 0.09% eU₃O₈ from 178.0 m

  • 0.5 m @ 0.11% eU₃O₈ from 183.8 m

• 18-575

  • 2.4 m @ 0.18% eU₃O₈ from 178.6 m

  • 1.2 m @ 0.31% eU₃O₈ from 184.0 m

Virtually all of the uranium mineralization in the Grants Uranium District is hosted by the Jurassic-aged Morrison Formation. The Westwater Canyon Member of the Morrison Formation hosts almost all of the known uranium mineralization in the Rio Puerco area (Figure 2). The interpreted ore zones consist of sandstone ribbons or lenses. The Westwater Canyon Member is underlain and overlain by the Recapture Shale and Brushy Basin Member of the Morrison Formation respectively, both of which consist dominantly of shale. The Jackpile Sandstone is a distinct sandstone unit within the Brushy Basin Member and it hosts significant uranium deposits elsewhere in the Grants Uranium District, including the historic Jackpile Mine located approximately 20 km southwest of Rio Puerco. The Jackpile Mine produced approximately 80 million pounds of U₃O₈ between 1952 and 1982. The Brushy Basin Member is unconformably overlain by the Cretaceous Dakota Sandstone and the Mancos Shale.

Rio Puerco 3-D Model Preparation
Drill collar locations from the 3-D model were determined from a map of drill hole locations prepared by Kerr-McGee for their drill programs in the 1960s and 1970s. The map was georeferenced and the collar locations were cross-referenced with georeferenced drill sections from the 2011 technical report². The 1975 consultant's report listed intersection depth and width and included a classification of significant drill intersections as either ore, strongly mineralized or weakly mineralized, for each drill hole completed across section 18 and section 24⁴. Using 3-D modelling software, drill hole traces were generated using available drill collar information that allowed for viewing and interpreting the continuity of significant drill intersections in 3-D space. In the zones where continuity between significant drill intersections was identified, holes had been drilled by Kerr McGee on an approximate 30 m grid.

RIO PUERCO WORK HISTORY AND HISTORICAL RESOURCE ESTIMATES
Rio Puerco is located at the eastern end of the Grants Uranium District which is the largest historic producer of uranium in the United States (Figure 3). Mines that operated between about 1950 and 2002 produced over 340 million pounds of U₃O₈. The district is currently seeing renewed exploration and development activity.

Uranium was first discovered at Rio Puerco in 1968. The claims covering the discovery were ultimately optioned to Kerr-McGee who drilled over 1,000 holes. Based on the results of that work, they began the development of the Rio Puerco Mine in the 1970s. The mine was intended to be a room and pillar underground mine but was never put into production. Activity ceased after a short trial mining phase due to low uranium prices at the time. The underground mine infrastructure included a 260 m vertical shaft, ventilation shafts, mining adits and support buildings. The mining shaft remains and road access to the site is excellent.

In 2009, Monaro Mining NL ("Monaro") commissioned an independent geological review and resource estimate for Rio Puerco using exploration data generated by Kerr-McGee in the 1960s and 1970s. The data used for the resource estimate consisted of historical maps and data from 764 drill holes including downhole gamma-ray data converted to percent equivalent U₃O₈ (eU₃O₈), geological logs and drillhole survey data. Monaro reported a JORC Code (2004)-compliant inferred resource of 6.0 million tonnes at an average grade of 0.09% eU₃O₈ using a cutoff grade of 0.03% eU₃O₈ for 11.4 million pounds of contained U₃O₈1. JORC is the Australian Joint Ore Reserves Committee, a professional code of practice that sets minimum standards for public reporting of Mineral Resources.

In 2011, Australian-American Mining Corporation Ltd. commissioned a technical report on Rio Puerco. This most recent report validated and confirmed the Historical Resource2.

The Historical Resource outlined in this news release has not been verified and should not be relied upon. It is a historical estimate and not current and does not comply with Canadian NI 43-101 guidelines for the reporting of Mineral Resources. The JORC Code (2004) is broadly consistent with the CIM Definition Standards adopted under NI 43-101, though differences may exist in the categorization of inferred resources. A Qualified Person has not verified the Historical Resource estimate on behalf of the Company and North Shore has completed no work programs at Rio Puerco. Though not current, the Company views the Historical Resource estimates as reliable and sufficient to justify the initiation of work programs aimed at validating and potentially expanding upon the estimates. There is no guarantee that the work programs envisioned by North Shore will ultimately result in the definition of NI 43-101-compliant resources.

The key assumptions, parameters, and methods used to prepare the Historical Resource estimate are described in the referenced technical reports.

The 64 BLM claims in the Project area are subject to the Rio Puerco Option Agreement under which North Shore has the right to acquire up to an 87.5% interest in Rio Puerco from Resurrection Mining LLC ("Resurrection"). Further information on Rio Puerco can be found in the Company's news releases dated June 24, 2025, August 28, 2025 and September 11, 2025.

ABOUT NORTH SHORE
The nuclear power industry is in growth mode as more nuclear power will be required to meet the world's ambitious CO₂ emission-reduction goals and the needs of new power-intensive technologies like AI. In this environment, new discoveries of economic uranium deposits will be very valuable, especially in established uranium-producing jurisdictions like Saskatchewan and New Mexico. North Shore is well-positioned to become a major force in exploration for economic uranium deposits. The Company is working to achieve this goal by exploring Rio Puerco in the Grants Uranium District of New Mexico and its Falcon and West Bear properties at the eastern margin of the Athabasca Basin in Saskatchewan. In addition, the Company continues to evaluate quality opportunities in the United States and Canada to complement its portfolio of uranium properties.

QUALIFIED PERSON
Mr. Brooke Clements, MSc, P.Geol., a Qualified Person as defined by National Instrument 43-101 - Standards of Disclosure for Mineral Projects and the President and CEO of North Shore, has reviewed and approved the scientific and technical disclosure in this press release.

Data Verification
Mr. Clements has reviewed and verified all of the data supporting the technical information disclosed in this news release. The data includes the 2009 and 2011 technical reports, the 3-D model prepared by North Shore showing interpreted uranium mineralization, the 1975 McDougald report, original hard copy and scanned drill hole location maps prepared by Kerr-McGee and plan maps from the Kerr-McGee underground mine development. As stated above, the Historical Resource outlined in this news release has not been verified, is not current and does not comply with Canadian NI 43-101 guidelines for the reporting of Mineral Resources. The original drill logs from the Kerr McGee drilling in the 1960s and 1970s that form the foundation for the 1975 McDougald report and the Historical Resource estimate have not been reviewed in detail.

ON BEHALF OFTHE BOARD
Brooke Clements,
President, Chief Executive Officer and Director

For further information:
Please contact: Brooke Clements, President, Chief Executive Officer and Director
Telephone: 604.536.2711
Email: b.clements@northshoreuranium.com
www.northshoreuranium.com

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 release.

Forward-Looking Statements
This news release contains forward-looking statements. All statements, other than statements of historical fact, that address activities, events, or developments that the Company believes, expects, or anticipates will or may occur in the future are forward-looking statements. These statements reflect management's current expectations based on information currently available and are subject to a number of risks and uncertainties that may cause actual results to differ materially from those discussed in the forward-looking statements. Forward-looking statements in this release include, but are not limited to: the Company's plans to confirm and expand upon the scale of uranium mineralization at the Rio Puerco project; the potential for in-situ recovery (ISR) mining at Rio Puerco; the initiation and results of work programs aimed at validating and potentially expanding upon historical resource estimates; the Company's ability to acquire up to an 87.5% interest in the Rio Puerco project and to create a joint venture with Resurrection Mining LLC; the Company's strategy to become a major force in uranium exploration and to evaluate additional opportunities in the United States and Canada; the actual results of current and planned exploration activities, including the potential for the definition of a mineral deposit of potential economic value at Rio Puerco and the Company's Falcon and West Bear properties in Saskatchewan; the ability of the Company to meet milestones and make bonus payments to Resurrection; the interpretation and meaning of completed and future geophysical surveys, drilling results, and economic evaluations; the availability of sufficient funding on terms acceptable to the Company and the timing and receipt of the required regulatory and government approvals to complete planned work programs including the planned drill program outlined in this news release; and other statements that are not historical facts. Forward-looking statements are frequently characterized by words such as "plan", "project", "appear", "interpret", "coincident", "potential", "confirm", "suggest", "evaluate", "encourage", "likely", "anomaly", "continuous" and variations of these words as well as other similar words or statements that certain events or conditions "could", "may", "should", "would" or "will" occur. These statements are subject to various risks and uncertainties that may cause actual results to differ materially from those anticipated or implied, including, but not limited to: the speculative nature of mineral exploration and development projects; the ability to obtain necessary permits and approvals; changes in project plans and parameters; variations in mineral grades and recovery rates; accidents, labour disputes and other risks of the mining industry; the availability of funding on terms acceptable to the Company; delays in obtaining governmental approvals or financing; fluctuations in metal prices including uranium; and other factors described in the Company's public disclosure documents. There may be other factors that cause actual results, performance, or achievements to differ materially from those anticipated or implied by the forward-looking statements. Any forward-looking statement speaks only as of the date on which it is made and, except as may be required by applicable securities laws, the Company disclaims any intent or obligation to update any forward-looking statement, whether as a result of new information, future events, or results or otherwise. Forward-looking statements are not guarantees of future performance and accordingly undue reliance should not be put on such statements due to the inherent uncertainty therein. Any forward-looking statements contained in this news release are expressly qualified in their entirety by this cautionary statement.

SOURCE: North Shore Uranium Ltd.