Northern Dynasty Minerals Ltd. announced, further to the Company's September 9, 2021 news release, that it has filed the "Preliminary Economic Assessment NI 43-101 Technical Report, Pebble Project, Alaska, USA" ("2021 PEA") at www.sedar.com. The technical report and an executive summary will also be posted on the Company's website at www.northerndynastyminerals.com. The PEA Technical Report will also be filed on EDGAR later this week. U.S. dollars and U.S. standard units are used unless otherwise indicated. All results are post-tax. Unless otherwise noted, all figures are based on forecast long-term metal prices. The 2021 PEA provides production, financial and cost estimates for its proposed Pebble Project (the "Proposed Project") in Southwest Alaska as described in the Pebble Project permit application and its amendments. The 2021 PEA also examines three potential mine expansion scenarios, each with a mine life that could reach more than 100 years, and potential scenarios for gold recovery that could form the basis for future permit applications and review. The Project could potentially provide more than $8 billion to the Southwest Alaska region through the Pebble Performance Dividend and the Lake and Peninsula Borough severance tax over the life of the potential expansion scenarios. This is in addition to the benefits that could flow from the existing and possible future agreements with Alaska Native Village Corporations. The Proposed Project detailed in the 2021 PEA is consistent with the Project Description in the Pebble EIS, as published by the USACE in July 2020. It does not include an onsite gold plant. The Proposed Project recently underwent a comprehensive review by the U.S. Army Corps of Engineers ("USACE"). This review culminated in their publishing of a Final Environmental Impact Statement ("FEIS") on July 24, 2020, which positively concluded ? among other things ? that the Proposed Project would "not have measureable effects" on fisheries in Southwest Alaska. The USACE subsequently issued a negative Record of Decision for the Project based, in part, on potential impacts to the fishery. Pebble Limited Partnership has filed an administrative appeal of the Record of Decision, arguing in part that the findings of potential impacts to the fishery were not adequately substantiated. As mentioned above, the 2021 PEA also examines three potential mine expansion scenarios, each with a mine life that could reach more than 100 years, and potential scenarios for gold recovery that could form the basis for future permit applications and review. These potential expansion scenarios were modelled on a mine development concept submitted by Northern Dynasty's 100%-owned U.S.-based subsidiary Pebble Limited Partnership ("Pebble Partnership") to the USACE during federal permitting in response to the federal agency's Request for Information ("RFI") about future potential mine development scenarios. For the Proposed Project and the potential expansion scenarios, the 2021 PEA also considers the impact of each on financial results of third parties owning and financing the construction of key transportation and power infrastructure, as is commonly the case in Alaska. It is assumed these third parties would either construct the facilities through their own resources or they would be included in overall project construction management. The Pebble Partnership would lease, operate and maintain the facilities as part of overall mine operations, with lease payments set to provide a market rate of return to lessors. With the exception of the Proposed Project, all development scenarios evaluated in the 2021 PEA are presented to demonstrate the optionality inherent in the polymetallic Pebble deposit by presenting a broad range of potential pathways for future mine development. Neither Northern Dynasty nor the Pebble Partnership has proposed or intends to propose any of these potential expansion scenarios in the near-term for regulatory approval. Any future development options beyond the Proposed Project would require extensive federal, state and local permitting processes and approvals before proceeding, which would be in addition to the initial permits and approvals required for the Proposed Project and, very importantly, in consultation with the people and communities of Western Alaska, as well as the State agencies. The 2021 PEA has been prepared within the guidelines established by National Instrument 43-101 ("NI 43-101") to disclose the current costs estimates and potential financial results for the Pebble Project. The Company is a "foreign issuer" under the U.S. Exchange Act and entitled to file continuous disclosure reports with the U.S. Securities and Exchange Commission under the Multi-Jurisdictional Disclosure System ("MJDS") between Canada and the United States, and to provide disclosure on our mineral properties, including the Pebble Project, in accordance with NI 43101 disclosure standards and CIM Definition Standards. For this reason, information contained in this news release in respect of the Pebble project may not be comparable to similar information made public by United States companies subject to the reporting and disclosure requirements under the United States federal securities laws and the rules and regulations thereunder.