Northern Dynasty: Compelling Summary Judgement Legal Briefs Filed Demonstrating Why the Veto is Illegal and Should be Withdrawn Immediately

Northern Dynasty: Compelling Summary Judgement Legal Briefs Filed Demonstrating Why the Veto is

Illegal and Should be Withdrawn Immediately

October 6, 2025 Vancouver – Northern Dynasty Minerals Ltd. (TSX: NDM; NYSE American: NAK) ("Northern

Dynasty" or the "Company") and its 100%-owned U.S.-based subsidiary Pebble Limited Partnership (“Pebble

Partnership”) announce that on October 3, 2025, they filed a Summary Judgement Brief in Alaska Federal

Court as did the State of Alaska, and Iliamna Natives Ltd. and Alaska Peninsula Corp. The arguments presented

clearly demonstrate the compelling reasons why the veto is illegal and should be withdrawn immediately.

“We are pleased to have filed the Summary Judgement Brief and to simultaneously be continuing our

settlement discussions with the government to remove this illegal veto ,” said Ron Thiessen, Northern

Dynasty’s President and CEO . “We believe we have a strong case and, along with our fellow plaintiffs, are

confident that we will win. And, frankly, we think the filing of this brief will help in our discussions with the

government because it clearly highlights agency overreach of its mandate and interference in a project that

is on state land which was designated, by statute, for mineral exploration and development. The facts cited

by EPA in its veto decision are directly contradicted by the Final Environmental Impact Statement (“FEIS”),

the official factual record in this proceeding.”

The arguments made in the Summary Judgement Brief are too numerous to list here, but a few of the

significant arguments on why the veto is illegal include:

A. The Environmental Protection Agency (“ EPA”) significantly underestimated the negative impact of the

very significant cost that its veto imposes on the economies of Alaska and the U.S., citing other U.S. projects

would simply make up the shortfall. Projects such as Pebble are unique and not easily replaced, let alone the

thousands of forgone jobs in Alaska . The economic analysis that was done was superficial, at best, and

ignored basic economic principles.

B. EPA has made it impossible to mine the deposit even though Congress specified that the state lands in

which Pebble is located should be available for mining. This violates the Alaska Statehood Act and The Cook

Inlet Land Exchange.

C. EPA relied on unsubstantiated speculation, rather than being able to make findings, that any harm to fish

populations and water habitats will actually occur; and the statute requires certainty, with scientific or factual

basis, not mere hypothetical, unsubstantiated speculation.

D. EPA's finding of an unacceptable adverse effect is irrational because it has no basis to conclude that the

very minor loss of streams at the mine site will actually lead to any decrease in salmon populations. This

finding is in direct contrast to what was extensively detailed in the comprehensive FEIS.

E. EPA's finding of an unacceptable adverse effect is also based on filling of wetlands. But now that the

Supreme Court has clarified which wetlands are regulated under the Clean Water Act, it's clear that the vast

majority of the Pebble lands are not even subject to that regulation as they would not and should not be

considered Jurisdictional Waters under the Clean Water Act.

Mr. Thiessen added, “We have submitted our brief per the timeline set by the court, and it is now up to the

government to review our case and to decide if they wish to file a response brief by January 2, 2026 to defend

the Obama/Biden veto in court . While the court proceeding advance s, our preferred option still remains

negotiating a prompt withdrawal of the illegal veto by the government and then dismissing the litigation.”

“In the meantime, the government has filed a request to stay the case in Alaska Federal Court, citing the U.S.

government shutdown that commenced on October 1, 2025 . We object to this request because it is our

strong preference to keep to the court ordered briefing schedule , which would require the government to

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respond by January 2, 2026. We have waited a long time for our day in court in this case, and we should not

have to wait any longer to vindicate our rights,” Mr. Thiessen concluded.

About Northern Dynasty Minerals Ltd.

Northern Dynasty is a mineral exploration and development company based in Vancouver, Canada. Northern

Dynasty's principal asset, owned through its wholly owned Alaska -based U.S. subsidiary, Pebble Limited

Partnership, is a 100% interest in a contiguous bl ock of 1,840 mineral claims in Southwest Alaska, including

the Pebble deposit, located 200 miles from Anchorage and 125 miles from Bristol Bay. The Pebble Partnership

is the proponent of the Pebble Project.

For further details on Northern Dynasty and the Pebble Project, please visit the Company's website at

www.northerndynastyminerals.com or contact Investor services at (604) 684-6365 or within North America

at 1-800-667-2114. Public filings, which include forward looking information cautionary language and risk

factor disclosure regarding the Company and the Pebble Project can be found in Canada at www.sedarplus.ca

and in the United States at www.sec.gov.

Ronald W. Thiessen

President & CEO

U.S. Media Contact:

Dan Gagnier, Gagnier Communications (646) 569-5897

Forward Looking Information and other Cautionary Factors

This document includes certain statements that may be deemed "forward -looking statements" under the United States Private

Securities Litigation Reform Act of 1995 and under applicable provisions of Canadian provincial securities laws. All statements in this

document, other than statements of historical facts, which address permitting, including the Company’s legal action against the U.S.

Environmental Protection Agency (“EPA”) and the U.S. Army Corps of Engineers (“USACE”), the withdrawal of the EPA veto and the

development and production for the Pebble Project are forward-looking statements. Additional forward looking statements made by

the Company under its continuous disclosure obligations include statements regarding (i) the development plan for the Pebble Project

(ii) the right-sizing and de-risking of the Pebble Project, (iii) the design and operating parameters for the Pebble Project development

plan, including projected capital and oper ating costs, (iv) the social integration of the Pebble Project into the Bristol Bay region and

benefits for Alaska, (v) the political and public support for the permitting process, (vi) the ability of the Pebble Project to ultimately

secure all required federal and state permits, (vii) the ability of the Company and/or the State of Alaska to challenge the EPA’s Final

Determination process under the Clean Water Act and ultimately the USACE’s Record of Dec ision (“USACE ROD ”) through legal

actions; (viii) exploration potential of the Pebble Project, (ix) future demand for copper, gold and other metals, (x) if per mitting is

ultimately secured, the ability to demonstrate the Pebble Project is ultimately commercially viable, and (xi) the potential addition of

partners in the Pebble Project. Although NDM believes the expectations expressed in these forward -looking statements are based

on reasonable assumptions, such statements should not be in any way be construed as guarantees that the Pebble Project will secure

all required government permits or regarding the ability of NDM to develop the Pebble Project in light of the USACE ROD and its

subsequent remand decision and the EPA’s Final Determination, establish the commercial feasibility of the Pebble Project, achieve

the required financing or develop the Pebble Project.

Forward-looking statements are necessarily based upon a number of factors and assumptions that, while considered reasonable by

NDM as of the date of such statements, are inherently subject to significant business, economic and competitive uncertainties and

contingencies. Assumptions used by NDM to develop forward-looking statements include the assumptions that (i) the Pebble Project

will obtain all required environmental and other permits and all land use and other licenses without undue delay, (ii) any fe asibility

studies prepared for the development of the Pebble Project will be positive, (iii) NDM’s estimates of mineral resources will not change,

and NDM will be successful in converting mineral resources to mineral reserves, (iv) NDM will be able to establish the commer cial

feasibility of the Pebble Project, and (v) NDM will be successful in its legal action against the EPA and the USACE and any action taken

by the EPA in connection with the Final Determination will ultimately not be successful in restricting or prohibiting develop ment of

the Pebble Project.

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In addition, the likelihood of future mining at the Pebble Project is subject to a large number of risks and will require achievement of

a number of technical, economic and legal objectives, including (i) the current development plan may not reflect the ultimate mine

plan for the Pebble Project, (ii) obtaining necessary mining and construction permits, licenses and approvals without undue del ay,

including without delay due to third party opposition or changes in government policies, (iii) finalization of the mine plan for the

Pebble Project, (iv) the completion of feasibility studies demonstrating that any Pebble Project mineral resources that can b e

economically mined, (v) completion of all necessary engineering for mining and processing facilities, (vi) the ability of NDM to secure

a partner for the development of the Pebble Project, and (vi) receipt by NDM of significant additional financing to fund these

objectives as well as funding mine construction. NDM is also subject to the specific risks inherent in the mining business as well as

general economic and business conditions. Investors should also consider the risk factors identified in the Company’s Annual

Information Form for the year ended December 31, 202 4, as filed on SEDAR+ (www.sedarplus.ca) and included in its annual report

on Form 40 -F filed on EDGAR (www.sec.gov), as well as the risk factors set out in the Company’s subsequent public continuous

disclosure filings available on SEDAR+ and EDGAR. For mor e information on the Company, Investors should review the Company's

filings with the United States Securities and Exchange Commission at www.sec.gov and its home jurisdiction filings that are available

at www.sedarplus.ca.

The National Environment Policy Act Environmental Impact Statement process requires a comprehensive “alternatives assessment”

be undertaken to consider a broad range of development alternatives, the final project design and operating parameters for th e

Pebble Project and associated infrastructure may vary significantly from that currently contemplated. As a result, the Company w ill

continue to consider various development options and no final project design has been selected at this time.