PERPETUA RESOURCES CORP. (PPTA) Business

Item 1. Business

Overview

The Corporation was incorporated under the BCBCA on February 22, 2011 under the name “Midas Gold Corp.” The Corporation changed its name to “Perpetua Resources Corp.” on February 15, 2021.

The Corporation’s head office is located at Suite 201 – 405 South 8th Street, Boise, Idaho, U.S.A. 83702 and its registered and records office is located at Suite 1008 – 550 Burrard Street, Vancouver, British Columbia V6C 2B5.

The Corporation is engaged in acquiring mining properties with the intention of exploring, evaluating, developing and placing them into production, if warranted. The Corporation’s principal mineral project is the Stibnite Gold Project (the “Project”) in Idaho, USA, which contains several gold, silver and antimony mineral deposits. The Corporation’s current focus is to redevelop three of the Deposits known as the Hangar Flats Deposit, West End Deposit and Yellow Pine Deposit, all of which are located within the Stibnite Gold Project, as well as reprocess certain historical tailings located on the Project. These development activities are intended to be undertaken in conjunction with a major restoration program designed to address legacy impacts related to historical mining activities in the Project area.

The Corporation’s subsidiaries’ hold the properties of the Stibnite Gold Project which are comprised of a contiguous package of unpatented federal lode claims, unpatented federal mill sites, patented lode mining claims and patented mill sites. As of December 31, 2025, this land position encompassed approximately 28,536 acres held in 1,674 unpatented lode claims and mill sites and patented land holdings. A subsidiary of the Corporation acquired these rights through a combination of purchases and transactions and staking under the 1872 Mining Law and holds a portion under an option agreement. Bureau of Land Management claim rental payments and filings are current as of the date of this filing and the claims are all held in good standing.

Construction of the Stibnite Gold Project and continuing exploration and development at and around the Project are expected to constitute the principal business of the Corporation for the coming years. In the course of realizing its objectives, the Corporation expects to enter into various agreements specific to the construction, development, financing and operation of the Project, as well as agreements to process or sell products.

On January 3, 2025, the USFS issued its ROD approving the 2021 Modified Mine Plan. On May 19, 2025, the USACE issued its ROD for the CWA Section 404 permit. Following receipt of the USFS ROD and USACE CWA Section 404 permit, the USFS approved the Plan of Operations, which is based on the ROD and the Modified Mine Plan, for the Project in October 2025. Upon placement of certain construction phase financial assurance and receipt of the required notices from USFS, IDL and USACE, the Company began early works construction for the Project on October 21, 2025. The Company is currently focused on advancing the Project towards a full construction decision for the Project in 2026, including finalizing the remaining permits and securing project financing.

Since August 2025, the Company has accelerated construction readiness and contracting activities for the Project. Recent milestones include completing basic engineering and advancing detailed engineering, commencing early works construction in October 2025 and appointing Hatch as the EPCM contractor. The Company has developed procurement packages for long lead time process plant equipment. An agreement was also reached with ATCO for the design, construction and installation of a 1,010-person turnkey camp accommodation and site package. Additionally, the Company issued a request for proposal from third parties to assess the technical and economic feasibility of off-site antimony processing facilities and on December 9, 2025, the Company announced a partnership with Idaho National Labs to conduct pilot-scale testing to produce antimony trisulfide for domestic uses. The Company also commenced an exploration and geotechnical core drilling program in the fourth quarter of 2025 through the beginning of the first quarter of 2026.

6

Table of Contents

Corporate Structure

The following chart shows the intra-corporate relationships between the Corporation and its subsidiaries. Perpetua Resources Idaho, Inc. (“PRII”) has no ownership interest in the Stibnite Gold Project; rather, it is the designated operating entity of the Corporation and manages Project activities. The property holding entity, Idaho Gold Resources Company, LLC (“IGRCLLC”), is the surviving entity in a merger with Stibnite Gold Company (“SGC”), effective June 3, 2021, and is managed pursuant to an operating agreement with PRII. PRII and IGRCLLC are wholly owned by the Corporation.

​

IGRCLLC holds title to the Yellow Pine, Hangar Flats and West End Deposits, all of the patented mill sites and all of the unpatented federal lode mining claims and unpatented mill sites.

Permitting and Environmental Matters

NEPA Permitting Update

Perpetua Resources is focused on the exploration and mining of the Stibnite Gold Project (the “Project”), the reclamation of prior deposits and historical tailings, and the restoration of the area to address historical activities and legacy contamination. The Project is, therefore, subject to numerous environmental regulations, including federal, state and local laws.

Significantly, we are subject to formal review under NEPA and extensive permitting requirements. In 2016, the USFS began its formal review of the Stibnite Gold Project under NEPA. The Forest Service completed scoping in 2017 and subsequently pursuant to the NEPA process, the USFS and cooperating agencies undertook extensive review of our project and proposed actions through a DEIS, released by the USFS in August 2020. In response to public and agency feedback on the DEIS, Perpetua Resources proposed modifications to the mine plan analyzed in DEIS Alternative 2 to include reduction of the project footprint, improvements in water quality, and lower water temperatures. Perpetua Resources submitted a refined proposed action to the USFS in October 2021 (the “Modified Mine Plan”).

The USFS then prepared a SDEIS to further evaluate the project refinements and compare the Company’s proposed site access via Burntlog Route to an alternative option using current roads. After nearly two years of review, the SDEIS was published on October 28, 2022 for a 75-day public comment period. The USFS identified the Modified Mine Plan as the Preferred Alternative and concluded that it would reasonably accomplish the purpose and need for consideration of approval of the Stibnite Gold Project, while giving consideration to environmental, economic and technical factors.

On September 6, 2024, the USFS published the FEIS and a DROD for the Stibnite Gold Project. The FEIS analyzes the potential environmental effects (including benefits) of the mining and reclamation activities proposed as part of the Stibnite Gold Project. The DROD outlined the USFS’s proposed decision to authorize the Modified Mine Plan and to approve a special use authorization for transmission line upgrades and installation of a new section of power transmission line with supporting infrastructure.

7

Table of Contents

On January 3, 2025, the USFS published the ROD and FEIS Errata approving the Modified Mine Plan for the Project, subject to Perpetua’s submittal of a Plan of Operations and USFS’ review and approval of the Plan of Operations. Per the requirements of the FEIS and ROD, Perpetua was required, among other things, to prepare for USFS review and approval a Plan of Operations based on the Modified Mine Plan and other plans comprising the suite of Environmental Monitoring and Management Plans. These plans were to incorporate Project updates as well as required mitigation measures, environmental protection measures, financial assurance and design features in this additional documentation. Perpetua submitted all required plans to USFS for its review.

On September 19, 2025, the USFS issued its conditional Notice to Proceed from the USFS for the Stibnite Gold Project, which stated the Project has satisfied the requirements outlined in the January 2025 ROD necessary to begin construction and that the Project may begin construction conditioned only on the Company posting of the joint construction phase financial assurance agreed to by USFS, IDL, and USACE for the Project.

Perpetua subsequently posted the agreed upon joint construction phase financial assurance for the Project, and the USFS on October 20, 2025, issued notice that the requirements necessary to start construction had been satisfied, the Plan of Operations had been approved and signed by USFS, and the Project could enter construction subject to terms and conditions specified in the notice. IDL and USACE on October 21, 2025, also issued notices confirming that the requirements necessary to begin construction under their respective approvals for the Project, including posting the agreed upon joint financial assurance, had been met and that the Company could begin construction subject to the terms and conditions identified by those agencies.

Following the USFS’ publication of the ROD and FEIS approving the Modified Mine Plan for the Project, lawsuits were filed against the USFS, USDA and other federal agencies on February 18, 2025, in the United States District Court for the District of Idaho by a number of environmental advocacy groups, including Save the South Fork Salmon, the Idaho Conservation League and other non-governmental organizations. The lawsuit alleges violations of NEPA and other federal laws in the regulatory process. Among other remedies, the claimants seek to vacate the ROD issued by USFS, the Final Biological Opinions issued by the U.S. Fish and Wildlife Service and the National Marine Fisheries Service on September 6, 2024, and October 7, 2024, respectively (together, the “Final Biological Opinions”), and other Project approvals and to enjoin any further implementation of the Project. PRII filed a motion to intervene in this lawsuit, which was granted by the district court on April 2, 2025.

On August 29, 2025, the Nez Perce Tribe filed a lawsuit against the USFS, United States Department of Agriculture and other federal agencies in the U.S. District Court for the District of Idaho challenging the USFS ROD and other approvals by the USFS and other federal agencies in connection with the Stibnite Gold Project and alleging violations of NEPA and other federal statutes, regulations, rules and requirements in the regulatory review and approval process in of the Project. Among other remedies, the Tribe seeks to vacate the USFS ROD and other Project approvals and to enjoin any further implementation of the Project. PRII filed a motion to intervene in this lawsuit, which was granted by the District Court on September 4, 2025.

The U.S. District Court on October 2, 2025 issued a general order staying all civil cases listed in the order due to the partial shutdown of the federal government over appropriations for the government. The list included the separate lawsuits filed by the Nez Perce Tribe and by the environmental advocacy groups mentioned above challenging the USFS ROD and other federal agency approvals. This stay does not affect the validity of the USFS ROD or any of the other approvals challenged in either of these lawsuits in connection with the Stibnite Gold Project, and all such approvals remain in effect. After the partial federal government shutdown ended, the District Court issued new scheduling orders in the two cases challenging the USFS ROD and other federal approvals. In the case involving the environmental advocacy groups, the scheduling order required all procedural and dispositive motions to be filed by January 20, 2026. Those pleadings have been filed by all parties. The District Court has not yet ruled on these pending motions. In the case involving the Nez Perce Tribe, all dispositive pleadings currently are required to be filed by the end of June 2026.

The two federal lawsuits referenced above remain pending. The Company believes the USFS ROD and other federal regulatory processes challenged in the two foregoing federal lawsuits were conducted thoroughly and completely by the relevant federal regulatory agencies. However, there can be no assurance that the Project approvals challenged in those two cases will be upheld upon judicial review.

On May 19, 2025, the USACE issued the CWA Section 404 permit for the Project, which included the Compensatory Mitigation Plan. USACE was a part of the review process as a cooperating agency since the Company began the federal NEPA process after filing the CWA Section 404 permit application in 2023. The CWA Section 404 permit was the last remaining federal permit needed to advance the Project towards a construction decision. On October 21, 2025, USACE issued a letter to the Company confirming that the conditions set forth in the CWA Section 404 permit necessary to begin construction, including posting of construction phase financial assurance, had been met.

8

Table of Contents

Before early works construction commenced as described in “Item 7. Management’s Discussion and Analysis of Financial Condition and Results of Operations – Engineering, Contracting and Construction Activities” section below, the Company entered into voluntary stipulations with the plaintiffs in the two above-mentioned federal lawsuits. Those stipulations. provide for certain restrictions on the early works construction activities for the Project until February 1, 2026, after which the stipulations will terminate on 30-days’ notice by the Company to the plaintiffs. In exchange for the Company’s commitments to these restrictions, the plaintiffs in each case agreed not to seek a preliminary injunction against development of the Project in conformance with the stipulations during the restriction period that will end when the stipulations terminate. These stipulations were filed with the U.S. District Court for the District of Idaho in the two federal lawsuits. On March 16, 2026, the Company provided notice to the plaintiffs that the stipulation restriction period will end 30 days from such notice.

Ancillary Permitting Update

With receipt of all federal permits, the Company is focused on advancing the Project towards a full construction decision, including finalizing the remaining state permits and securing project financing. Most state permits for the Project were issued as of December 31, 2025, with certain previously submitted permit applications continuing through the administrative review process as of that date. In January 2026, IDEQ issued an IPDES individual industrial wastewater discharge permit), and IDWR issued the final stream alteration permit. The IPDES industrial discharge permit is subject to an automatic stay in connection with pending administrative appeal under state law as discussed in “Item 3. Legal Proceedings” section below. IDEQ continues to review Perpetua’s application for an IPDES sanitary waste discharge permit. In July 2025, IDEQ released a draft modification to its CWA Section 401 water quality certification for public comment. The Company anticipates receiving the IPDES sanitary discharge permit by early Q2 2026 and anticipates that IDEQ will issue the final modification of its Section 401 certification in Q2 or Q3 2026. IDEQ’s CWA Section 401 certification is subject to an ongoing state administrative contested case challenge.

See “Item 7. Management’s Discussion and Analysis of Financial Condition and Results of Operations – Ancillary Permitting Activities” below.