North Shore Uranium Confirms Uranium Mineralization in All 13 Phase 1 Holes at Rio Puerco

North Shore Uranium Confirms Uranium Mineralization in All 13 Phase 1 Holes at Rio Puerco

VANCOUVER, BC – September 3, 2026 – North Shore Uranium Ltd. (TSX-V: NSU | OTCQB: NSURF), a featured company in The Resource Vault, has reported results from Phase 1 of its first drill program at the Rio Puerco uranium project in northwestern New Mexico.

The program was designed to test and validate historic Kerr-McGee drilling that underpins a non-current historical resource estimate at Rio Puerco. North Shore completed 13 vertical rotary holes totaling 9,274 feet (2,828 metres). Every hole intersected significant uranium mineralization using the Company’s stated cutoff of 0.02% eU₃O₈ and a minimum grade-thickness product of 0.30.

The result matters because validation is the first step in turning decades-old drilling data into a modern geological model and, potentially, a future NI 43-101 compliant resource estimate. The work is not complete, and the historical resource is not current. But the first 13 holes have confirmed uranium mineralization where the historical data indicated it should be.

“We confirmed significant uranium mineralization in all 13 drill holes and all 21 uranium intercepts were below the water table, a favourable characteristic in the evaluation of ISR mining,” said Brooke Clements, President and CEO of North Shore Uranium. “We are especially encouraged with the grade and thickness of the intersections, including RP-26-18-39 where a 27 ft interval had a grade of 0.30% eU₃O₈.”

Phase 1 Drill Highlights

Intervals are assumed to approximate true widths because holes were vertical and the mineralized sandstone horizons are interpreted as horizontal. eU₃O₈ is an equivalent uranium grade calculated from calibrated downhole gamma logging. It has not been verified by chemical assay, and actual uranium grades may vary.

This Was a Validation Program

Rio Puerco is not a blind exploration target. Uranium was discovered there in 1968, and Kerr-McGee subsequently drilled more than 1,100 holes in the immediate area. Historical work led to development of underground mine infrastructure, including a 260-metre shaft and crosscuts, although the mine did not enter commercial production after uranium prices collapsed in the early 1980s.

A 2009 historical estimate, based on Kerr-McGee data, reported 6.0 million tonnes at 0.09% eU₃O₈ containing 11.4 million pounds of U₃O₈. North Shore does not treat that estimate as current, and it is not NI 43-101 compliant. The purpose of the 2026 drill program is to test whether the original data can be verified and incorporated into new technical work.

Each Phase 1 hole was drilled beside a historic Kerr-McGee hole where uranium mineralization had previously been identified through natural gamma logging. North Shore confirmed uranium mineralization at all 13 of those sites. The mineralization occurs in three stacked sandstone units of the Westwater Canyon Member, the same units reported to host more than 95% of the contained uranium in the historical resource.

Figure 1. Generalized stratigraphic section at Rio Puerco. The Phase 1 program confirmed uranium mineralization in the Westwater Canyon sandstone units, including JmwB, JmwC, and JmwD. These are the principal horizons associated with the historical resource estimate.

Why the Water Table Matters

All 21 reported uranium intercepts were below the water table. This is a favourable characteristic for the early-stage evaluation of potential in-situ recovery, or ISR, mining.

ISR generally requires uranium mineralization to occur in a saturated and suitably permeable host rock. The Phase 1 results establish that the reported mineralized intervals are below the water table. They do not establish ISR amenability on their own. Hydrogeological, metallurgical, engineering, environmental, and permitting work would still be required before any mining method could be selected.

The combination of grade, thickness, sandstone-hosted mineralization, and position below the water table provides North Shore with a solid technical basis for the next phase of evaluation.

A Second Horizon to Watch

North Shore also reported uranium mineralization, not included in the main results table, in the shallower Jackpile Sandstone. This is a separate exploration horizon above the Westwater Canyon Member.

The Jackpile Sandstone hosted the historic Jackpile Mine, approximately 20 kilometres southwest of Rio Puerco, which produced about 80 million pounds of U₃O₈ between 1952 and 1982. The presence of mineralization in this separate unit adds another exploration target, although it remains early-stage.

Figure 2. Rio Puerco lies at the eastern end of New Mexico’s Grants Uranium District, the largest historic uranium-producing district in the United States. North Shore’s project is located near advanced exploration and development-stage projects including Roca Honda, Marquez-Juan Tafoya, and Cebolleta.

What Comes Next

North Shore plans a Phase 2 drill program for the fourth quarter of 2026. The combined Phase 1 and Phase 2 results are expected to support further validation of the historic database and preparation of geological and resource models.

A future NI 43-101 resource estimate is not guaranteed. However, the first phase has done what it was designed to do: it has verified significant uranium mineralization in each of the historic areas tested, providing a stronger basis for the next technical step.

The Resource Vault Perspective

The important point in this release is not simply that North Shore reported several strong intervals. It is that all 13 twin holes confirmed the historic mineralized zones. For a company working to validate a non-current resource estimate, consistency across every test hole is the right result.

Rio Puerco already has a substantial history, existing underground infrastructure, and a historic estimate that North Shore is seeking to bring up to modern reporting standards. The Company now has fresh field data from the same sandstone horizons and a clear Phase 2 plan for later this year.

For investors, the next milestone is whether Phase 2 can provide the remaining validation needed to move toward a compliant resource model. That is the point at which the historical Rio Puerco dataset may begin to carry more weight in the market.

For the full North Shore Uranium investment report, visit the North Shore Uranium Company Page on The Resource Vault.

→ Read Our Initiation Report: “A Historical Uranium Resource in America’s Most Prolific Uranium District”

Qualified Persons

The scientific and technical information in the source release was reviewed and approved by Brooke Clements, MSc, P.Geol., President, CEO and Director of North Shore Uranium, and a Qualified Person as defined by NI 43-101. The drill program was managed in the field by Chris Longton, Principal Geologist with Rangefront Mining Services, also a Qualified Person under NI 43-101. James Thom, a North Shore director and a Competent Person in Australia, analyzed the Phase 1 results and supporting historic exploration data under Mr. Clements’ supervision.

Data Verification and Quality Control

North Shore used calibrated multi-parameter downhole geophysical logging to collect natural gamma ray, resistivity, and spontaneous-potential measurements. eU₃O₈ grades were estimated from natural gamma-ray data using standard correction and calibration factors. These grades are not chemical assays. The Company states that its Qualified Person reviewed and verified the Phase 1 gamma-probe data and associated grade estimation.

About North Shore Uranium Ltd.

North Shore Uranium is advancing uranium exploration at the Rio Puerco project in the Grants Uranium District of New Mexico and at its Falcon and West Bear properties on the eastern margin of Saskatchewan’s Athabasca Basin. The Company also evaluates uranium opportunities in the United States and Canada. North Shore trades on the TSX Venture Exchange under the symbol “NSU” and on the OTCQB under the symbol “NSURF.”

Cautionary Statement

The historical resource estimate cited in this release is not current, has not been verified by a Qualified Person on behalf of North Shore Uranium, and should not be relied upon. It does not comply with NI 43-101. There is no certainty that further work will result in the definition of a current NI 43-101 mineral resource. This release contains forward-looking statements, including statements about the Phase 2 drill program, validation of historic data, future geological and resource modelling, and the potential evaluation of ISR mining. Actual results may differ materially from those anticipated.

Disclosure: The companies promoted on The Resource Vault have been disseminated on behalf of Equity Catalyst Partners, LLC. Equity Catalyst Partners, LLC has been engaged by these companies to provide marketing and investor relations services and is compensated by each company. This is not financial advice.