American Uranium’s early infill drilling at Lo Herma confirms robust uranium mineralisation continuity in Mine Unit 1, setting the stage for a resource upgrade and scoping study in Q3 2026.
- 61% of first 18 holes hit mineralisation above cutoff
- Best intercept: 1.06 GT over 5.8m at 0.056% eU3O8
- Drilling aims to convert Inferred to Indicated resources
- 55-hole program one-third complete with expansion planned
- Q3 2026 update and scoping study targeted
Early Drilling Confirms Strong Mineralisation Continuity
American Uranium Limited (ASX:AMU) has delivered encouraging early results from its ongoing infill drilling program at the Lo Herma ISR uranium project in Wyoming. Of the first 18 holes drilled within Mine Unit 1, 11 intercepted uranium mineralisation above the 0.02% eU3O8 cutoff grade, with eight exceeding the target grade-thickness (GT) threshold of 0.2. The standout hole, LH-26-026, returned a grade thickness of 1.06 over 5.8 metres at 0.056% eU3O8, underscoring the strength of the deposit’s continuity.
This drilling campaign, which is roughly one-third complete with 3,243 metres drilled out of a planned 55 holes, is primarily focused on converting Inferred resources to the higher confidence Indicated category within Mine Unit 1. This is a critical step to underpinning the upcoming Mineral Resource Estimate (MRE) update and the planned Scoping Study targeted for Q3 2026.
Resource Upgrade and Expansion Strategy
The program also includes step-out drilling in Mine Unit 2, aiming to expand the resource base along projected redox trends to the south. American Uranium’s CEO Bruce Lane highlighted that this dual approach of infill and expansion drilling is designed to enhance resource confidence and grow the overall resource inventory, which currently stands at 9.45 million pounds of uranium across Lo Herma’s mine units, based on the March 2026 update.
Mr Lane emphasised the strategic importance of these results in advancing Lo Herma towards in-situ recovery (ISR) mining development, particularly given the strengthening uranium market and increasing U.S. policy emphasis on domestic nuclear fuel security. The company’s drilling builds on a comprehensive historical dataset acquired in 2023, which includes over 1,700 drill holes from the 1970s and 1980s, providing a robust foundation for resource modelling.
Technical Approach and Project Context
The drilling methodology employs vertical mud rotary holes with geophysical logging to measure natural gamma emissions, converted into equivalent uranium grades (eU3O8). This approach, standard in U.S. uranium exploration, allows for accurate estimation of mineralised thickness due to the flat-lying nature of the deposits. The project benefits from proximity to established ISR uranium facilities in the Powder River Basin, a prolific uranium-producing region since the 1970s.
Alongside drilling, ongoing hydrogeological testing, including aquifer pump tests, is designed to support future mine development planning. The company’s resource upgrade strategy aims to increase the proportion of Indicated resources, which currently represent about 46% of the total 7 million pounds contained uranium across Mine Units 1 to 3.
Near-Term Catalysts and Funding
With the drilling campaign underway since early May 2026, American Uranium is progressing towards delivering an updated MRE and Scoping Study by Q3 2026. These milestones are expected to provide greater clarity on project economics and development pathways. The company’s recent capital raising activities, including a rights issue extended to 3 June 2026, aim to fund these technical programs and support Lo Herma’s advancement entitlement offer backed by updated Wyoming resources and extended rights issue deadline.
While the current results reinforce confidence in the deposit’s continuity, the actual conversion from Inferred to Indicated resources will depend on the final assay data and geological modelling. Additionally, assumptions regarding radiometric disequilibrium remain preliminary, with further core testing planned to validate these factors.
Bottom Line?
The coming months will be pivotal as American Uranium seeks to translate strong drilling continuity into a meaningful resource upgrade, a key step toward unlocking Lo Herma’s development potential.
Questions in the middle?
- How will the upcoming Q3 resource update impact project valuation and financing?
- What will further hydrogeological testing reveal about ISR feasibility at Lo Herma?
- How might evolving U.S. nuclear fuel policies influence Lo Herma’s development timeline?