Saturday, September 26, 2026
MiningNewsTerminal
Saturday, September 26, 2026 Admin

PPTA.TO ·

Perpetua Resources Celebrates Stibnite Gold Project Advancing to Development with State and Federal Officials Governor of Idaho, U.S. Army, Department of Defense, and U.S. Department of Agriculture officials among those at Stibnite Gold Project celebration kick-off

Corporate Updates

405 S 8th Street #201, Boise, ID 83702

NEWS RELEASE

September 19 , 2025

Perpetua Resources Celebrates Stibnite Gold Project Advancing to Development

with State and Federal Officials

Governor of Idaho, U.S. Army, Department of Defense, and U.S. Department of Agriculture

officials among those at Stibnite Gold Project celebration kick-off

Celebration follows U.S. Forest Service Notice to Proceed, indicating Project may begin

development upon posting of financial assurance

Perpetua committed to support U.S. Defense Department ‘Ground-to-Round’ Strategy

BOISE, ID – Perpetua Resources Corp. (Nasdaq: PPTA / TSX: PPTA) (“Perpetua Resources” or “Perpetua”

or the “Company”), hosted leaders from across the country at the historical Stibnite Mining District to

celebrate the Stibnite Gold Project (the “Project”) advancing to development after more than 8 years of

rigorous permitting review. Idaho Governor Brad Little, U.S. Department of Agriculture Deputy

Undersecretary Kristin Sleeper, and U.S. Army Major General John Reim were among those who

attended and spoke at the event . All the speakers emphasized the Project’s pivotal role in America’s

national security and defense.

“American readiness starts here,” said Perpetua President & CEO Jon Cherry. “After years of thoughtful

consideration, public feedback , and intensive review, we are ready to secure American antimony .

Backed by the financial power of gold production and a plan to provide meaningful environmental

benefits to this historical site, today marks a new chapter in American resilience . We could not be

prouder of our work to provide urgently needed antimony for our military defense.”

Perpetua Board of Directors, Senior Leaders, U.S. Department of Agriculture Deputy Undersecretary

Kristin Sleeper, and Maj. Gen. John T. Reim (From left to right)

Responsible Mining. Critical Resources. Clean Future.

2

Earlier today, the Company announced that the U.S. Forest Service had delivered a conditional Notice

to Proceed, officially recognizing that Perpetua Resources has satisfied the requirements of the Record

of Decision and stating that the Project may move into development upon posting the required financial

assurance. The Project, a listed FAST-41 Transparency Project and recipient of $80 million in Department

of Defense funds, is expected to produce America’s only mined reserve of the critical mineral antimony,

a key component in munitions and advanced defense systems . In addition, the Project is designed to

clean up legacy contamination, reconnect fish to their native spawning grounds, restore habitat, and

provide hundreds of family-wage jobs.

Jon Cherry, Idaho Governor Brad Little, U.S. Department of Agriculture Deputy Undersecretary Kristin

Sleeper, and Maj. Gen. John T. Reim (From left to right)

Given the significant and urgent need to supply American antimony, Perpetua expects to begin early

works construction this fall at the Project . During Friday’s ceremony, Cherry presided over a ribbon

cutting for Perpetua’s antimony stockpile, signaling readiness to provide the U.S. military with a critically

needed supply of antimony from the Stibnite Gold Project.

“The Stibnite project currently holds the largest identified reserve of antimony in the U.S. It is one of the

largest antimony reserves outside of foreign control. This mine offers a secure, reliable, domestic

resource for military grade antimony sulfide and is aligned with the Army’s ongoing ‘Ground-to-Round’

assured munitions strategy for establishing a complete domestic supply chain, from raw material access

to material processing to ammunition production , as we modernize and fortify the Arsenal of

Democracy,” said Maj. Gen. John T. Reim, Joint Program Executive Officer Armaments & Ammunition

and Picatinny Arsenal Commanding General.

The Stibnite Gold Project is expected to supply up to 35 percent of U.S. antimony demand during its

first six years of operations based on the 202 5 USGS antimony commodity summary . Antimony is

classified as a critical mineral essential for technology, defense, and energy applications. China

Responsible Mining. Critical Resources. Clean Future.

3

dominates global antimony mining, processing, and refining, account s for about 80% of all U.S.

antimony imports and, in 2024 , China cut off antimony exports. Developing a domestic source of

antimony through the Stibnite Gold Project is imperative to America’s security and strategic mineral

independence. The Project is projected to be one of the highest -grade open -pit gold mines in the

United States, with gold reserves of approximately 4.8 million ounces, and is expected to produce

approximately 450,000 ounces of gold annually over its first four years of production. The financial

backing of gold production is expected to support the concurrent production of a steady, reliable source

of domestic antimony. The U.S. National Defense Stockpile of antimony trisulfide currently holds limited

supply for peacetime demand , and the Stibnite Project is well positioned to commence antimony

production and reduce the United States’ reliance on foreign adversaries for this critical resource.

Joining the refrain from Washington, DC, U.S. Senator James Risch (R -Idaho) cheered the Project’s

advancement.

“A strong domestic supply of critical minerals is vital to America’s future. For too long, excessive

regulations have stifled important mining projects, forcing us to rely on foreign adversaries for resources

readily available in our own backyard. Today’s news and President Trump’s actions to expand U.S.

mineral production are welcome signs that times are changing,” said Risch. “As one of the largest

sources of antimony outside of Beijing’s control, the Stibnite Gold Mine will bolster our national security,

military readiness, and the Gem State economy. The U.S. must remain a leader in the global race for

critical minerals, and I am proud that Idaho is at the forefront of this effort.”

Jon Cherry, Idaho Governor Brad Little, Maj. Gen. John T. Reim, and U.S. Department of Agriculture

Deputy Undersecretary Kristin Sleeper (From left to right)

Responsible Mining. Critical Resources. Clean Future.

4

The historical Stibnite Mining District saw a century of mining and produced a secure supply of

antimony vital to the Allied war effort in World War II (after the U.S.’s primary source from China was cut

off) before it was abandoned by past operators . Now, t he Stibnite Gold Project is positioned to once

again provide a domestic source critical to U.S. national security and deliver significant environmental

and economic benefits to rural Idaho . The Project is designed to reduce the environmental

contamination left behind by previous operators, reconnect fish to their native spawning grounds, and

restore habitat. To date, the Company has spent more than $20 million to improve water quality on site

and cleaned up more than 375,000 tons of legacy waste and tailings. The Project is also expected to

bring significant investment to the region, creating more than 950 jobs during construction and over

550 jobs during operations.

“Idaho is proud to celebrate this milestone with Perpetua Resources and showcase the ways we are

moving forward valuable projects that create hundreds of good -paying jobs that support Idaho’s rural

economy. These jobs will allow Idaho’s young people to buil d rewarding careers right here in the

communities of the West Central mountains,” Governor Brad Little said. “This is exactly the kind of

transformative project I want the SPEED Council to embrace. Idaho remains committed to a transparent

and streamlined regulatory process to enhance the economic vitality our state and Idahoans’ quality of

life.”

During the kick-off ceremony, Cherry presented the Stibnite Foundation with a $350,000 check to share

the benefits of the Stibnite Gold Project with the region. The Stibnite Foundation is a 501(c)(3) charitable

foundation built to empower the people, environment and communities located closest to the Stibnite

Gold Project today and long after the mine closes. It was formed as part of the Company’s Community

Agreement. To date, Perpetua has donated $750,000 and given the Foundation 150,000 shares in the

company. Pursuant to the Community Agreement, Perpetua will continue making financial contributions

as the Project reaches key milestones, and will switch to a profit-sharing partnership during operations.

“It has always been important to our team that the Stibnite Gold Project has a positive impact on our

surrounding communities,” said Cherry. “Investing in the Stibnite Foundation allows us to work side-by-

side with our neighbors and help them address issues that are most important to them.”

For further information about Perpetua Resources Corp., please contact:

Chris Fogg

Investor Relations Manager

[email protected]

[email protected]

Mckinsey Lyon

Vice President External Affairs

[email protected]

Website: www.perpetuaresources.com

About Perpetua Resources and the Stibnite Gold Project

Perpetua Resources Corp., through its wholly owned subsidiaries, is focused on the exploration, site

restoration and redevelopment of gold -antimony-silver deposits in the Stibnite -Yellow Pine district of

central Idaho that are encompassed by the Stibnite Gold Project. The Stibnite Gold Project is one of the

highest-grade, open pit gold deposits in the United States and is designed to apply a modern,

responsible mining approach to restore an abandoned mine site and produce both gold and the only

mined sourc e of antimony in the United States. Antimony trisulfide from Stibnite is the only known

domestic reserves of antimony that can meet U.S. defense needs for many small arms, munitions, and

missile types.

Responsible Mining. Critical Resources. Clean Future.

5

FORWARD-LOOKING INFORMATION

Investors should be aware that the Company has not entered into any arrangement with respect to the

joint financial assurance bonding and may not be able to enter into such arrangements on the anticipated

terms and timeline, or at all. In addition, such arrangement, when entered into, may not be sufficient to

satisfy the financial assurance conditions required to commence construction as set forth in the Notice.

Investors should be aware that the Stibnite Gold Project’s designation as a Transparency Project and

inclusion in the FAST-41 Program does not imply endorsement of, or support for, the Stibnite Gold Project

by the federal government, or create a presumptio n that the Stibnite Gold Project will be approved,

favorably reviewed by any agency or receive federal funding. The designation of a project as a

Transparency Project and inclusion in the FAST -41 Program may be reconsidered based on updated

information.

Statements contained in this news release that are not historical facts are "forward -looking information"

or "forward -looking statements" (collectively, "Forward -Looking Information") within the meaning of

applicable Canadian securities legislation and the United States Private Securities Litigation Reform Act

of 1995. Forward -Looking Information includes, but is not limited to, the Company’s ability to satisfy

financial assurance requirements under applicable federal and state law on acceptable terms and on

anticipated timelines, if at all; disclosure regarding the anticipated effects of the SPEED Act; the

Company’s ability, in connection with efforts to satisfy financial assurance requirements applicable to the

Stibnite Gold Project and to provide additional financing, to enter into an arrangement on acceptable

terms and on the anticipated timeline, if at all; the occurrence of the expected benefits from the Project,

including providing a domestic source of antimony, national defense benefits , creation of jobs,

environmental benefits; expected benefits from the Stibnite Foundation and other community initiatives;

the number and nature of jobs expected to be created. In certain cases, Forward-Looking Information can

be identified by the use of words and phrases or variations of such words and phrases or statements such

as "anticipate", "expect", "plan", "likely", "believe", "intend", "forecast", "project", "estimate", "potential",

"could", "may", "will", "would" or "should". In preparing the Forward-Looking Information in this news

release, Perpetua Resources has applied several material assumptions, including, but not limited to, that

the Company will be able to satisfy all conditions provided in various federal and state permits that must

be met to commence construction; that the Company will be able to satisfy financial assurance

requirements applicable under applicable federal and state law; that the Company’s proposed financing

package will be sufficient to finance permitting, pre -construction and construction of the Stibnite Gold

Project or that the Company will be able to secure alternate financing if necessary; and that the current

exploration, development, environmental and other objectives concerning the Project can be achieved

and that its other corporate activities will proceed as expected. Forward-Looking Information are based

on certain material assumptions and involve, known and unknown risks, uncertainties and other factors

which may cause the actual results, performance or achievements of Perpetua Resources to be materially

different from any future results, perfor mance or achievements expressed or implied by the Forward -

Looking Information. Such risks and other factors, among other things, risks related to unforeseen delays

in the review and permitting process, including as a result of legal challenges to the ROD or other permits;

risks related to opposition to the Stibnite Gold Project; risks related to increased or un expected costs in

operations or the permitting process; risks that necessary financing will be unavailable when needed on

acceptable terms, or at all, as well as include those factors discussed in Perpetua Resources' public filings

with the U.S. Securities and Exchange Commission (the "SEC") and its Canadian disclosure record.

Although Perpetua Resources has attempted to identify important factors that could affec t Perpetua

Resources and may cause actual actions, events or results to differ materially from those described in

Forward-Looking Information, there may be other factors that cause actions, events or results not to be

as anticipated, estimated or intended. There can be no assurance that Forward-Looking Information will

prove to be accurate, as actual results and future events could differ materially from those anticipated in

such statements. Accordingly, readers should not place undue reliance on Forward-Looking Information.

For further information on these and other risks and uncertainties that may affect the Company's business,

see the "Risk Factors" and "Management's Discussion and Analysis of Financial Condition and Results of

Responsible Mining. Critical Resources. Clean Future.

6

Operations" sections of the Company's filings with the SEC, which are available at www.sec.gov and

with the Canadian securities regulators, which are available at www.sedarplus.com. Except as required

by law, Perpetua Resources does not assume any obligation to release publicly any revisions to Forward-

Looking Information contained in this news release to reflect events or circumstances after the date hereof

or to reflect the occurrence of unanticipated events.

Cautionary Statement Regarding Reserve and Technical Information

The reserves information in respect of the Stibnite Gold Project in this news release is based upon

information contained in the technical report titled “Stibnite Gold Project, Feasibility Study Technical

Report, Valley County, Idaho” dated effective December 22, 2020 and issued January 27, 2021 (the “2020

Feasibility Study”), which is summarized in the Company’s Technical Report Summary, dated as of

December 31, 2021, and amended as of June 6, 2022 (the “TRS”). Such information is as of December

30, 2020 and is subject to the assumptions, exclusions and qualifications set forth in the 2020 Feasibility

Study and the TRS. The 2020 Feasibility Study was prepared in accordance with National Instrument 43 -

101 – Standards of Disclosure for Mineral Projects and th e TRS was prepared in accordance with the

mining property disclosure rules specified in Subpart 1300 promulgated by the SEC. For additional

information regarding the TRS and the 2020 Feasibility Study, as well as the Company’s 2025

supplemental financial update, investors are encouraged to refer to the Company’s Form 10-K for its fiscal

year 2024, filed with the SEC on March 19, 2025. Data regarding domestic antimony reserves based on

U.S. Geological Survey, Mineral Commodity Summaries, dated as of January 2025.