American Uranium Ltd (ASX:AMU, OTC:GTRIF) has kicked off resource development drilling at its flagship Lo Herma in-situ recovery (ISR) Uranium Project in Wyoming’s Powder River Basin, targeting growth and upgrades to its existing 8.57-million-pound (Mlb) uranium resource.
The company said Phase 1 drilling — the first part of a two-phase campaign — is now under way and will focus on expanding the current resource base ahead of an interim mineral resource estimate (MRE) update expected in early 2026.
“We are delighted to have now commenced Phase 1 of the resource development drilling campaign at Lo Herma,” said American Uranium CEO and executive director Bruce Lane.
“This program marks an important step towards advancing one of America’s most promising near-term, low-cost ISR uranium projects,” he added. “Lo Herma is one of the few near-term, low-cost IRS projects in the US, and the drilling campaign will target both growth in the current 8.57Mlb resource base and increased confidence in Mineral Resources.
“This work is expected to feed into a further resource upgrade and updated scoping study in the first half of 2026 to demonstrate Lo Herma’s potential to deliver similar economic potential to ISR uranium mines currently being planned or constructed in Wyoming such as Ur-Energy’s Shirley Basin project.”
Two-phase development program
The company’s drilling permit allows for up to 121 holes (about 37,500 metres) across the proposed Mine Units 1 and 2, supporting both expansion and classification upgrades.
- Phase 1: Around 50 holes (~15,000 metres) of step-out drilling will test extensions of known mineralised rollfronts, mainly to the north of the two proposed mine units.
- Phase 2: About 71 holes (~22,500 metres) are scheduled for early 2026, aimed at converting a larger share of the current resource — of which 32% is in the Indicated or Measured category — to higher-confidence classifications.
The upcoming scoping study update, due in the second quarter of 2026, will incorporate results from both phases, providing a clearer picture of Lo Herma’s potential production capacity and economics.
Strong progress at Wyoming flagship
Located in the heart of the Powder River Basin, Lo Herma ranks among a handful of new ISR uranium developments positioned to help rebuild domestic US supply as global demand for nuclear fuel accelerates.
Drilling follows the early mobilisation of a rig last month and builds on steady operational momentum.
Read more: Drill rig mobilised ahead of schedule at Lo Herma in-situ recovery uranium project
The company is targeting Lo Herma as its first development asset within a broader US uranium growth strategy.