Boise, Idaho -- September 01, 2026 -- Perpetua Resources Corp. (Nasdaq: PPTA; TSX: PPTA) said dual autoclaves for its Stibnite Gold Project in central Idaho are now being fabricated at a custom facility in Europe, one of several construction milestones the company detailed on August 31, 2026. Four drill rigs have completed roughly 5,800 meters of a 10,000-meter 2026 exploration program that has returned high-grade gold, antimony and tungsten intercepts. The update follows an August 18, 2026 ruling by the U.S. District Court of Idaho upholding federal approvals for the project, and a July 29, 2026 ribbon-cutting for a military antimony processing plant at Idaho National Laboratory.
Curved Steel Plates Are Rolled to Exact Autoclave Specifications
Perpetua submitted purchase orders earlier this year for the dual autoclaves that will anchor the Stibnite processing facility. The vessel components, curved plates rolled to match the autoclave's specified radius before welding, are classified by the company as long-lead equipment items central to gold extraction at the site.
Half of Housing Units Reach Stibnite, Remainder Staged 75 Miles Away
As of August 24, 2026, roughly half of the ATCO-supplied modular units for Stibnite's permanent Worker Housing Facility had been delivered to the site. The remaining units are staged in Cascade, Idaho, 75 miles from the project, with deliveries arriving nearly every day. Grading and utility installation at the permanent housing location are complete, and temporary workforce housing is already operating on site.
Forest Service Names Burntlog Route the Preferred Access Path
Construction crews are building out the project's Administrative Pad, which will house emergency services and support facilities, alongside the Burntlog Route. The U.S. Forest Service designated Burntlog as the "preferred alternative" and "environmentally preferred alternative" under the National Environmental Policy Act; once finished, it will serve as the main access road to Stibnite.
Four Rigs Find High-Grade Gold and a New Tungsten Zone
Exploration crews have logged approximately 5,800 meters of a 10,000-meter drill program across four rigs. In the Clark Tunnel Fault Zone, near the southeastern edge of the Yellow Pine pit, drilling returned 6.4 meters at 16.2 grams per tonne gold and 1.7% antimony from surface, plus 15.0 meters at 6.3 g/t gold and 0.8% antimony starting at 11 meters depth. The same zone yielded a new gold-tungsten discovery of 21.3 meters at 3.2 g/t gold and 0.9% tungsten from a 24-meter depth, with scheelite mineralization observed in subsequent holes.
The Huckleberry Fault Zone, adjacent to the Yellow Pine reserve pit, returned 69.6 meters at 0.8 g/t gold, comparable to grades at the nearby West End pit. At Hangar Flats, near-surface drilling hit 3.0 meters at 14.5 g/t gold, while deeper holes beneath the reserve pit returned 22.9 meters at 3.2% antimony and 1.2% tungsten, 9.8 meters at 8.3% antimony and 4.6% tungsten, and 3.4 meters at 10.6% antimony and 1.5% tungsten. Perpetua noted that any tungsten development would require separate environmental review outside the project's current permitted scope.
Army Funding for Antimony Plant Reaches $87 Million Since 2022
Perpetua, the U.S. Army and Idaho National Laboratory held a ribbon-cutting on July 29, 2026, in Idaho Falls for a modular mineral processing plant that will convert antimony samples from Stibnite into antimony trisulfide for military ammunition. Idaho Governor Brad Little, Lieutenant Governor Scott Bedke and Congressman Mike Simpson attended the event, which followed China's 2021 cutoff of U.S. antimony access. Since 2022, Perpetua has received more than $87 million from the U.S. Department of War and Army, including over $59 million in Defense Production Act funds and a $4.7 million award that brought total Army funding under the Ordnance Technology Initiative Agreement to $27 million.
Stibnite holds the only identified antimony reserve in the United States. According to a National Register of Historic Places filing referenced by the company, the site supplied more than 90% of the antimony and more than 50% of the tungsten used by the U.S. government during World War II.
Idaho Court Upholds Federal Approvals, Sends One Issue Back to Wildlife Service
The U.S. District Court of Idaho ruled on August 18, 2026, that the U.S. Forest Service and other federal agencies properly approved the Stibnite Gold Project, rejecting claims that the decisions violated the National Environmental Policy Act, the General Mining Law and the National Forest Management Act. The court also upheld the agencies' Endangered Species Act findings that the project would not jeopardize protected species, though it remanded the Incidental Take Statements to the U.S. Fish and Wildlife Service to clarify monitoring and reporting measures. Plaintiffs have filed an appeal, but Perpetua said it is continuing critical path construction based on the ruling and an earlier denial of a preliminary injunction motion.
"We continue to see tangible progress at Stibnite," said Jon Cherry, President and CEO of Perpetua Resources.
Perpetua opened The Outpost, a community resource and visitor center in Yellow Pine, Idaho, on July 16, 2026, offering educational displays and project updates to residents and visitors.