Highlights

  • American Uranium surged 28.57% to $0.135 on volume of 526,468 shares after reporting a meaningful interim resource upgrade at its Lo Herma ISR Uranium Project in Wyoming's Powder River Basin, with the Mineral Resource Estimate growing approximately 10% to 9.45 million pounds of eU3O8, including 4.02 million pounds now classified at the higher-confidence Indicated category representing 43% of the total resource.
  • The combined uranium Mineral Resource Estimate across AMU's Wyoming projects — including the Great Divide Basin — has grown to 11.11 million pounds eU3O8, with the Lo Herma Exploration Target Range also expanded following new drilling and claims staking, providing a growing geological foundation for the Scoping Study targeted for Q3 2026.
  • With 66 of 121 permitted drill holes completed and 55 infill and expansion holes remaining for Q2 2026, the company is at the halfway point of a resource development program designed to support a further resource upgrade and Scoping Study incorporating intensive hydrogeological and metallurgical analysis ahead of a potential In-Situ Recovery development pathway.

On Tuesday 31 March 2026, American Uranium Ltd (ASX:AMU) delivered a sharp and material single-session share price gain, closing at $0.135 — up $0.030 or 28.57% — on volume of 526,468 shares. The bid and offer range at the close sat at $0.135 on both sides of the market, suggesting that demand had absorbed available supply at the session's closing price with no residual offer overhang at that level. With a market capitalisation of approximately $11.24 million, AMU sits firmly in the micro-cap segment of the ASX, where company-specific geological and operational newsflow can produce outsized single-session price reactions against a backdrop of limited institutional coverage and thin daily liquidity.

The catalyst for Tuesday's move was unambiguous and operationally substantive. American Uranium released an interim update to the Mineral Resource Estimate at its Lo Herma ISR Uranium Project in Wyoming's Powder River Basin, reporting approximately 10% growth in the total resource to 9.45 million pounds of equivalent uranium oxide, alongside a meaningful improvement in resource confidence through an increase in the proportion of Indicated-category material. For investors tracking the uranium exploration and development space on the ASX, this type of incremental but genuine resource growth — particularly when accompanied by confidence category upgrades — represents precisely the kind of milestone that can materially shift market perceptions of a project's development trajectory.

American Uranium and Its Wyoming Strategy: The ISR Opportunity

To appreciate the significance of the Lo Herma resource update, it is necessary to understand both the company's strategic positioning and the specific production methodology it is pursuing. American Uranium Ltd is an ASX and OTCQB dual-listed uranium exploration and development company whose principal asset base is concentrated in the state of Wyoming in the United States — one of the most historically significant and geologically prospective uranium jurisdictions in North America.

The company's flagship asset is the Lo Herma ISR Uranium Project, located in Converse County within Wyoming's Powder River Basin, approximately 15 miles north of the town of Glenrock. The development methodology targeted for Lo Herma is In-Situ Recovery — a uranium mining technique that involves the circulation of a leaching solution through a uranium-bearing ore body in place, dissolving the uranium underground and pumping the uranium-laden solution to surface for processing. ISR mining avoids the need for conventional open-pit or underground excavation, dramatically reducing the capital intensity, surface disturbance, and operational cost profile of uranium production compared to conventional mining methods.

The ISR approach is particularly well-suited to Wyoming's Powder River Basin, which has a long and well-documented history of roll-front uranium deposits — the geological configuration most amenable to ISR extraction. The basin has hosted uranium production since the 1970s and is home to multiple operating, permitted, or previously operating ISR uranium processing facilities, including UEC's Willow Creek complex incorporating Irigaray and Christensen Ranch, the permitted Ludeman ISR project, Cameco's Smith Ranch-Highland ISR facilities, and Energy Fuels' Nichols Ranch ISR plant. The proximity of Lo Herma to this established ISR infrastructure ecosystem is strategically meaningful, as it provides potential future optionality around toll processing arrangements or infrastructure partnerships that could further reduce the standalone capital requirements for the project.

The regional context extends further to include Ur-Energy's operating Lost Creek ISR facility and its Shirley Basin satellite, referenced by American Uranium in regional comparisons given their production and advanced ISR development status. For a company positioning Lo Herma as a future ISR producer, the ability to point to multiple analogous and operating nearby projects as validation of the basin's production credentials is a meaningful element of the project's geological and commercial narrative.

The Historical Data Advantage: A Foundation Built on Legacy Knowledge

One of the more distinctive aspects of American Uranium's approach to the Lo Herma project is the manner in which it assembled its geological knowledge base. As reported to the ASX in March 2023, the company acquired a comprehensive historical data package for the Lo Herma region with an estimated replacement value of over A$15 million. This package contained original data for approximately 1,771 drill holes representing roughly 530,000 feet — or approximately 162,000 metres — of drilling conducted in the Lo Herma region by prior operators over decades of historical exploration activity.

The acquisition of this legacy dataset provided American Uranium with an extraordinarily rich geological foundation from which to build its resource development program without incurring the cost of re-drilling what was effectively already well-characterised ground. The original drill data was used to prepare an initial Inferred Mineral Resource Estimate and Exploration Target Range for Lo Herma, which was then followed by a 26-hole exploration program in the winter of 2023 and a 73-hole resource development drill program in the summer of 2024. These successive programs have progressively validated and extended the historical data, building confidence in the resource model and supporting the category upgrades that have been reported in successive MRE updates.

This approach — leveraging existing historical data to establish a geological foundation before committing capital to new drilling — is a capital-efficient strategy that allowed AMU to establish a credible resource base at relatively low cost. It also means that successive drilling campaigns are now focused on converting and expanding a known resource rather than testing conceptual geological targets, which provides a higher probability of continuing success with each drill result reported.

The Interim Resource Update: Scale and Confidence Both Improving

The core of Tuesday's announcement is the interim Mineral Resource Estimate update for Lo Herma, which reports total mineralisation of 5.93 million tonnes at an average grade of 720 parts per million equivalent uranium oxide for a contained metal inventory of 9.45 million pounds of eU3O8. This compares to the prior estimate of 8.57 million pounds, representing growth of approximately 10% in the total resource. Critically, the update also records a meaningful improvement in resource confidence, with 4.02 million pounds — representing 43% of the total resource — now classified in the Indicated category, up from the previous distribution. The remaining 5.43 million pounds is classified as Inferred.

The distinction between Indicated and Inferred resource categories is significant and warrants explanation for investors less familiar with the JORC Code framework under which Australian-listed companies report mineral resources. An Indicated Mineral Resource is one where the quantity, grade, density, shape, and physical characteristics are estimated with sufficient confidence to allow the application of Modifying Factors in sufficient detail to support mine planning and evaluation of the economic viability of the deposit. An Inferred Resource, by contrast, is characterised by lower geological confidence, relying on limited information and reasonable assumptions. The conversion of resource tonnes from Inferred to Indicated therefore represents a genuine improvement in the quality and reliability of the resource estimate — not merely a change in nomenclature.

The MRE is reported at a cut-off grade of 200 parts per million uranium oxide and a minimum grade-thickness of 0.2 per mineralised horizon, parameters that are specifically calibrated for ISR mining economics and consistent with industry standards for ISR uranium resource reporting in Wyoming. The grade-thickness product is a particularly important metric in ISR uranium resource assessment, as it captures the combined effect of uranium concentration and mineralised interval thickness on the economics of in-situ leaching.

Within the planned Scoping Study footprint — specifically Mine Units 1, 2, and 3 — the combined resources now stand at 7.00 million pounds, with 46% of this sub-total now in the Indicated category. The concentration of the resource within the planned Mine Units area, and the higher proportion of Indicated material in this zone, is directly relevant to the Scoping Study work, as Scoping Studies typically require a minimum proportion of Indicated resources to produce economically meaningful production schedules and financial modelling. The improvement in confidence within the Mine Units footprint therefore represents a direct enabler of the Scoping Study timeline.

The Exploration Target and Total Wyoming Portfolio

Beyond the Lo Herma resource itself, American Uranium has also updated its Exploration Target Range for the project following new drilling results and the staking of additional claims. The updated Exploration Target Range is reported at between 5.79 and 7.54 million tonnes at a grade range of 500 to 700 parts per million uranium oxide — a range that has expanded from its initial reporting in July 2023, through an increase in December 2024, and now again with the current update. The Exploration Target is not a Mineral Resource and does not have the same level of geological confidence, but it provides a directional indication of the additional resource potential that the company believes exists within the Lo Herma tenement area beyond what has been incorporated into the current MRE.

When combined with the Great Divide Basin project, AMU's total Wyoming uranium Mineral Resource Estimate now stands at 11.11 million pounds of uranium oxide. This multi-project resource base provides the company with a degree of geological diversification across Wyoming's key uranium districts and a larger platform of pounds in the ground from which to build the development case for the broader portfolio.

Drilling Progress and the Path to Scoping Study

The current resource update is an interim milestone within a larger 121-hole drill program that remains ongoing. As of the announcement date, 66 of the 121 permitted holes had been completed, with 55 remaining holes planned for execution during Q2 2026. These remaining holes include both infill drilling — designed to increase resource confidence by filling spatial gaps in the current drill pattern — and expansion holes targeting potential resource extensions beyond the current MRE boundary.

The completion of the remaining 55-hole program will feed into a further resource update and Scoping Study targeted for Q3 2026. The Scoping Study will incorporate the updated resource model alongside intensive hydrogeological and metallurgical analysis — the two additional technical work streams that are critical to defining an ISR development pathway. Hydrogeological analysis characterises the groundwater flow regime in which ISR leaching will occur, including the aquifer characteristics, hydraulic conductivity, and potential for solution migration, all of which directly influence the design and permitting of wellfield patterns. Metallurgical analysis assesses the amenability of the uranium mineralisation to ISR leaching chemistry, determining the efficiency with which uranium can be extracted from the ore body under various chemical conditions.

Together, the completion of drilling, the updated resource model, and the hydrogeological and metallurgical datasets will provide the technical foundation for a Scoping Study that defines a preliminary development pathway — including a mine plan, capital cost estimate, operating cost estimate, and indicative financial model — for the Lo Herma ISR project. A Q3 2026 Scoping Study would represent a significant developmental milestone for the company and is likely to be a material catalyst for future market re-rating if the study delivers credible economics.

The Uranium Market Backdrop

The Lo Herma resource development story unfolds against a uranium market backdrop that has experienced significant price movements in recent years, driven by growing recognition of nuclear energy's role in decarbonisation strategies across major economies. The structural demand outlook for uranium has been strengthened by policy decisions across Europe, Asia, and North America to extend the life of existing nuclear plants, advance new reactor construction programs, and include nuclear energy as a component of net-zero transition strategies. The United States in particular has been active in supporting domestic uranium production through policy measures aimed at reducing dependence on foreign — particularly Russian — uranium supply chains.

Wyoming's established ISR uranium production infrastructure and regulatory track record make it one of the most shovel-ready uranium jurisdictions in the United States for new ISR project development. For a company like American Uranium, which is advancing a project in this jurisdiction toward a Scoping Study, the alignment between the project's development timeline and the structural uranium market dynamics is an important contextual factor. The proximity to operating ISR facilities and the potential for toll processing arrangements provide additional optionality that could meaningfully reduce the capital requirements and timeline to production for Lo Herma, relative to a project requiring entirely standalone processing infrastructure.

Share Price Context and Investor Considerations

At $0.135 per share and a market capitalisation of approximately $11.24 million, American Uranium remains a micro-cap exploration company at an early but advancing stage of its development journey. The 28.57% single-session gain on Tuesday reflects the market's positive reassessment of the resource update as a genuine step forward in the project's maturation toward a development decision. The even bid-offer spread at $0.135 at the close suggests a degree of price equilibrium at the session's close, with neither residual selling pressure nor unfilled buying demand dominating the order book at that level.

Investors in stocks at this stage of development and scale should be cognisant of the practical realities of micro-cap uranium exploration. The path from an interim resource update to a completed Scoping Study, through to a development decision, project financing, construction, and first production, involves multiple technical, financial, regulatory, and market-related milestones, each of which carries execution risk. The uranium price, which is set by global markets beyond the company's control, will be a significant determinant of whether Lo Herma's economics are compelling at the time a development decision is required.

Conclusion

American Uranium Ltd's Tuesday share price performance reflects the market's recognition of a genuine and meaningful step forward in the geological and technical development of the Lo Herma ISR Uranium Project. The growth of the Mineral Resource Estimate to 9.45 million pounds with 43% in the higher-confidence Indicated category, the expansion of the total Wyoming portfolio to 11.11 million pounds, and the clear pathway toward a Q3 2026 Scoping Study incorporating the remaining 55-hole drill program together constitute a credible and advancing development narrative. The company's strategic positioning within Wyoming's Powder River Basin — one of North America's most established ISR uranium jurisdictions — and its leverage to the structural uranium demand outlook provide a broader investment context that extends well beyond the single-session share price movement. The Scoping Study, when delivered, will be the next major milestone against which the market will assess whether the geological progress of the past three years is translating into a commercially viable development proposition.