PERPETUA RESOURCES CORP.

The Corporation and its subsidiaries have been parties to an ongoing legal proceeding with the Nez Perce Tribe for claimed violations of the CWA allegedly linked to historical mining activities. In August 2019, the Nez Perce Tribe filed suit in the United States District Court for the District of Idaho. The Company filed an answer generally denying liability and later, the court allowed the Company to amend and file a third-party complaint against the Forest Service. The Company also filed a separate CWA citizen suit against the USFS alleging that several of the point source discharges, as alleged by the Nez Perce Tribe in its complaint, were occurring on lands owned and controlled by the United States government.

Pursuant to the terms of the voluntary ASAOC executed in January 2021 with the U.S. EPA and the USDA, the Company agreed to dismiss its pending actions against the Forest Service without prejudice. On August 8, 2023, the Company and the Nez Perce Tribe filed a final Settlement Agreement (the “Settlement Agreement”) to resolve the tribe’s CWA litigation. The parties jointly asked the court to approve the Settlement Agreement and dismiss the case without prejudice. The Settlement Agreement provides for total payments of $5.0 million by Perpetua over a four-year period. This includes $4.0 million of contributions by Perpetua to a South Fork Salmon Water Quality Enhancement Fund (the “Fund”) to be used by the Nez Perce Tribe to support water quality improvement projects in the South Fork Salmon River watershed and $1.0 million of reimbursements to the Nez Perce Tribe for legal expenses. Following a

45-day review period by the United States Justice Department and the U.S. EPA, the U.S. District Court for the District of Idaho approved the Stipulation for Dismissal and entered a Judgment on October 2, 2023, which resulted in the CWA lawsuit being dismissed without prejudice. Under the Settlement Agreement, the Company anticipates that a dismissal with prejudice is contemplated after completion of Perpetua’s required payments. All required payments to date have been made timely pursuant to the terms of the settlement. As of December 31, 2024, the current portion of the settlement was $1,000,000 with the remaining $2,000,000 classified as long-term. See Note 9e to the Consolidated Financial Statements.

Certain of the Company’s property interests in the Project site are also subject to existing judicial consent decrees entered into by third parties and various governmental entities. These consent decrees, which impose environmental liability and remediation responsibilities on third parties, apply to certain mining claims and mill sites acquired by Perpetua from those third parties. Under the consent decrees, Perpetua is required to grant access to certain Project site areas by regulatory agencies and allow remediation activities to proceed if necessary and preserve the integrity of previous response actions. Several of the Company’s patented claims in the Hangar Flats and Yellow Pine properties are also subject to a consent decree which requires Perpetua to cooperate with the U.S. EPA and the USFS to implement appropriate response activities.

Additionally, following the USFS’ publication of the ROD and FEIS authorizing the Modified Mine Plan for the Project, claims were filed against the USFS, the USDA and other federal agencies on February 18, 2025 in the United States District Court for the District of Idaho by a number of claimants, including Save the South Fork Salmon, the Idaho Conservation League and other non-governmental organizations, alleging violations of NEPA and other federal laws in the regulatory process. Among other remedies, the claimants seek to vacate the ROD, FEIS, Final Biological Opinions and Project approvals and enjoin any further implementation of the Project. PRII has filed a motion with the court to intervene in this lawsuit. The Company believes the federal permitting process was conducted thoroughly and completely by the relevant federal regulatory agencies. However, there can be no assurance that the ROD, FEIS, and other Project approvals will be upheld upon judicial review.