American Uranium Ltd has commenced large-scale hydrogeological pump testing at Mine Unit 1 of its Lo Herma in-situ recovery uranium project in Wyoming's Powder River Basin.

The program is centred on the existing LH MW-003 pumping well and incorporates four observation wells spaced approximately 400 to 500 feet away in the target Middle C Sand production horizon. Additional monitoring installations include a piezometer in the overlying A Coal seam, a 5-inch well in the overlying D Sand, and an underlying sand monitoring well to evaluate hydraulic connectivity and potential responses in adjacent geological units.

The current large-scale configuration builds on late 2025 hydrogeological testing that evaluated four monitoring wells. That earlier work demonstrated sustained flow rates and minimal aquifer drawdown, with consultant Petrotek Corporation concluding the characteristics were consistent with other operating in-situ recovery facilities in Wyoming's southern Powder River Basin.

Data collected from the ongoing pump tests will generate groundwater modelling inputs, support permitting activities, and establish wellfield development parameters across the proposed initial mining area. American Uranium targets the delivery of an updated Scoping Study for the project in the fourth quarter of 2026.

“With our updated 9.96Mlb resource completed and pump testing now underway, Lo Herma continues to advance toward development. The program will deliver key data for groundwater modelling, permitting and ISR wellfield design.”

— Bruce Lane, CEO and Executive Director

The field program follows an August 2026 resource update that increased total mineral resources at the project to 9.96 million pounds of U3O8, up from the previous estimate of 8.57 million pounds. Within the proposed Scoping Study footprint across Mine Units 1, 2 and 3, resources reached 7.38 million pounds of U3O8, with 54 percent classified in the indicated category. Mine Unit 1 is the company's most advanced proposed mine unit and is currently expected to form the initial stage of development evaluated in the planned Scoping Study.

Elsewhere in the district, Premier American Uranium Inc. reported its strongest drill results to date from its Kaycee uranium project on 18 August 2026, highlighting ongoing regional activity across the Powder River Basin.

Read the full announcement: Large-Scale Aquifer Testing Commences at Lo Herma