American Uranium Limited (ASX:AMU) progresses hydrogeological testing and drilling at Lo Herma ISR Project

American Uranium Limited has advanced the technical foundations of its Lo Herma ISR Project in Wyoming’s Powder River Basin, completing a major phase of hydrogeological testing while continuing an extensive drilling program designed to support a 2026 Mineral Resource Estimate update.

The latest field activities provide further clarity on subsurface conditions central to in situ recovery development and expand geological confidence across the areas earmarked for future production planning.

Highlights

• Hydrogeological testing completed on all monitor wells, with sustained flows and minimal aquifer drawdown.
• Petrotek’s test report expected before the end of 2025.
• Resource expansion drilling ongoing north of proposed Mine Units 1 and 2.
• Continuity of mineralised sands and redox conditions observed.
• Drilling to continue to Christmas, with results expected at program completion ahead of the 2026 MRE update.
• Work programs are targeting improved resource and hydrogeologic confidence for a planned 2026 Scoping Study update.

The company reports that hydrogeological testing at Lo Herma has been finalised, marking an important milestone in assessing aquifer transmissivity and verifying conditions required for ISR development.

The testing was conducted by Petrotek Corporation, a consultancy with extensive experience across Wyoming’s uranium districts, and included step drawdown assessments and sustained pumping across four previously installed monitor wells.

Field operations were supported by Central Wyoming Water Well Service, which supplied equipment and ensured consistent testing protocols covering flow rates, water level responses and related hydrogeological indicators.

All wells demonstrated stable flows with minimal drawdown for the full duration of the program.

In parallel, American Uranium has maintained momentum on its resource expansion drilling campaign, which began on October 21, 2025 north of proposed Mine Unit 1 where 31 holes have been completed targeting extensions of earlier interpreted mineralisation at depths of approximately 275 metres.

Activity then shifted to the area north of proposed Mine Unit 2, where a substantial 2024 discovery remains open along trend and where seven holes have been drilled to date targeting deeper sand units reaching approximately 425 metres.

Early observations confirm continuity of mineralised sand units and redox conditions across both areas.

American Uranium CEO and Executive Director Bruce Lane said:

“We are very pleased that the hydrogeological testing program at Lo Herma has been completed as scheduled, with all wells demonstrating sustained flows and minimal aquifer drawdown for the full duration of the tests. The initial test observations are highly encouraging, and we look forward to receiving Petrotek’s report before the end of the year. Resource expansion drilling has also been progressing as planned, with continuity of mineralised sands and redox conditions observed in the areas north of the proposed Mine Units 1 and 2.”

Access road improvements north of Mine Unit 1 are also progressing to support drill rig movements, with additional drilling expected ahead of the Christmas shutdown period and drilling results to be released after completion of the full program and an initial assessment of the dataset.

With both hydrogeological and drilling programs advancing toward the company’s planned 2026 technical updates, Lo Herma continues to move along a structured ISR development pathway typical of Wyoming’s uranium sector.

The convergence of validated aquifer performance and expanding drill coverage provides a stronger foundation for future resource modelling and for refining the next iteration of the Scoping Study.

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