Demand the Army Corps stop the first Ambler Road mine

Record closed November 2, 2026

A river below Brooks Range peaks, Alaska, from the air — Comments closed November 2
Demand the Army Corps stop the first Ambler Road mine
U.S. Army Corps of Engineers · Subarctic Creek, Kobuk River

What: The Ambler Road is meant to reach this mining district, and the Arctic mine is the first one to seek a federal permit.
Where: Subarctic Creek, Kobuk River, Ambler Mining District, AK
How much: Wetlands and waters filled for good: 120.7 acres. Total footprint: 1,727.2 acres. Ore processed a day: 11,000 short tons.
Decided: Comments closed November 2, 2026. No decision document is on file yet.Date from Army Corps of Engineers public notice POA-2019-00081 ↗, read October 9, 2026.

Where these four lines come from

WhatOur plain-English read of the Army Corps public notice ↗. Check it against the agency’s own words under Case.
WhereThe places and states the notice names, as PLAN read them.
120.7 acres“Fill placement would result in permanent impacts to approximately 120.7 acres (48.9 ha) of wetlands and other waters” Corps notice, p. 2 Open the document at p. 2 ↗
1,727.2 acres“The Project would have a total disturbance footprint of approximately 1,727.2 acres (699 hectares [ha])” Corps notice, p. 2 Open the document at p. 2 ↗
11,000 short tons“The Project is designed to process approximately 11,000 short tons per day” Corps notice, p. 1 Open the document at p. 1 ↗
DecidedNovember 2, 2026, from Army Corps of Engineers public notice POA-2019-00081, notice of intent ↗: “EXPIRATION DATE: November 2, 2026”. Read October 9, 2026. The decision document is the one on file in PLAN’s record.
Read from PLAN’s record November 14, 2026.

Our reportingOur Ambler Road investigation →

What the proposal said, and what the decision did

No figure from the proposal has been checked against the decision on this fight yet. What the record does hold is the issues ledger below.

No decision document is on PLAN’s record for this fight yet. When the agency’s decision lands, what it answered goes here.

PLAN's read: critical threat

A language model's read of the agency's notice, not an agency rating and not an editor's finding. It’s read from the official notice ↗, and it isn’t a grade.

The Ambler Road is meant to reach this mining district, and the Arctic mine is the first one to seek a federal permit.

What’s at risk

The mine would permanently fill 120.7 acres of wetlands and other waters, hold its tailings behind a dam at the headwaters of Subarctic Creek, and run about 13 years, with water treatment continuing after it closes. The applicant's parent company prices that treatment at $1,095 million undiscounted over a 100-year closure period, or $258 million discounted. The upper Kobuk supports the largest spawning sheefish population in northwestern Alaska, and between 88 and 95 percent of households in the Kobuk River communities use caribou.

If this goes through

Scoped to a single pit, the draft EIS, which the company expects in October 2027, can leave out the Bornite deposit, the claims the road opens, who pays for water treatment after closure and the dust along the haul, and the Corps would decide by September 2028 without answering any of them. Scoping is when the Corps sets the issues, alternatives and data gaps the draft has to address, so what's raised by November 2 goes on the list it has to answer.

Our plain-English read of the official notice ↗. Check it against the agency’s own words below.

By the numbers, from the documents on the record

Wetlands and waters filled for good: 120.7 acres
Corps notice, p. 2
“Fill placement would result in permanent impacts to approximately 120.7 acres (48.9 ha) of wetlands and other waters”
Open the document at p. 2 ↗
Total footprint: 1,727.2 acres
Corps notice, p. 2
“The Project would have a total disturbance footprint of approximately 1,727.2 acres (699 hectares [ha])”
Open the document at p. 2 ↗
Ore processed a day: 11,000 short tons
Corps notice, p. 1
“The Project is designed to process approximately 11,000 short tons per day”
Open the document at p. 1 ↗
Operating life: about 13 years
Corps notice, p. 2
“Construction is expected to require approximately 3 years followed by an anticipated operating life of approximately 13 years.”
Open the document at p. 2 ↗
Water treatment over the 100-year closure period, undiscounted ($258 million discounted): $1,095 million
Trilogy Metals Form 10-K, fiscal 2025, p. 59
“amounting to $1,095 million over the 100-year closure period. These costs equate to $258 million when discounted at 4.3% p.a. to the first year of post-production.”
Open the source ↗
EIS record of decision due: September 15, 2028
Corps notice, p. 6
“USACE plans to issue a Record of Decision concluding the EIS by September 15, 2028”
Open the document at p. 6 ↗

Testing the agency’s case

What the agency argues, and whether its own record backs it

2
Hold up: 2
Not fully backed

The Army Corps of Engineers plans to prepare an environmental impact statement before it decides whether to issue a Section 404 permit for Ambler Metals' open-pit Arctic Mine. The fill for the mine and roads would permanently affect about 120.7 acres of wetlands and other waters. The Corps says a full review is required because the mine could significantly affect water, fish, wildlife, subsistence and the regional economy.

“USACE has determined that the Project has the potential to result in significant impacts to aquatic resources, water quality, fish and wildlife resources, subsistence uses, and regional socioeconomic conditions.”
Project Background

Purpose and needNot fully backedThe project is needed to bring domestic supplies of critical minerals to market, as well as to maximize value for Ambler Metals.
The notice gives some support. The project was added to the Federal Permitting Dashboard under Executive Order 14241, Immediate Measures to Increase American Mineral Production. The ore would come from the Arctic Deposit in northwestern Alaska, which is a domestic source, and shipping concentrate to smelters or refineries outside of Alaska doesn't by itself make the supply foreign. Still, the notice never says which of copper, zinc, lead, gold and silver count as critical minerals. It also doesn't say whether the smelters or refineries are in the United States.
The agency’s words, the record +Hide the words
The agency says
“The primary need for the Project is to bring domestic supplies of critical minerals to market and maximize value to Ambler Metals LLC.”
Purpose and Need
Elsewhere in the same document
“In Fairbanks concentrate would be transferred to rail for transport to Anchorage, where it would be loaded onto marine vessels for shipment to smelters or refineries outside of Alaska.”
Project Description
AlternativesNot fully backedReasonable alternatives will be those that are technically, legally and economically feasible and that meet the identified project purpose and need, developed through scoping.
The notice commits to studying more than the applicant's plan. It lists a no action alternative, alternatives that avoid, minimize and compensate for impacts both inside and outside the project footprint, and alternatives using alternative practices, all to be developed through scoping. The stated need also includes bringing domestic supplies of critical minerals to market, not only maximizing value to Ambler Metals. Still, the applicant's purpose is to extract minerals profitably with proven, economical methods. The notice doesn't explain how much weight that company goal will carry in deciding which alternatives are reasonable.
The agency’s words, the record and the law +Hide the words
The agency says
“Reasonable alternatives that are technically, legally, and economically feasible and also meet the identified Project purpose and need will be developed through the scoping process.”
Alternatives
Elsewhere in the same document
“The applicant’s purpose is to profitably extract commercial quantities of copper, zinc, lead, and other valuable minerals from the Arctic Deposit ore reserves using proven and economical mining and milling methods.”
Purpose and Need
The law
“consistent with the provisions of this chapter, study, develop, and describe technically and economically feasible alternatives;” National Environmental Policy Act, 42 U.S.C. 4332(2)(F) ↗

Where its own record backs the agency

AuthorityThe Corps can decide this project through a Section 404 permit because building it requires discharging fill into waters of the United States.Why it holds +
The Project Description says fill placement would permanently affect about 120.7 acres of wetlands and other waters. That's the kind of fill discharge the cited permit covers, and the figures add up: 110.6 acres of wetlands plus 10.1 acres of ponds and streams. The notice doesn't say which permit would cover the treated water piped into Subarctic Creek, but that gap doesn't weaken the fill permit's reach.
The agency says
“Ambler Metals LLC submitted a complete application for a Section 404 permit to USACE on May 19, 2026 to authorize discharge of fill material into waters of the United States required to construct the Project.”
Project Background
Its own record backs it
“Fill placement would result in permanent impacts to approximately 120.7 acres (48.9 ha) of wetlands and other waters including approximately 110.6 acres (44.8 ha) of wetlands and 10.1 acres (4.1 ha) in other waters (i.e., ponds and streams).”
Project Description
ProcessScoping gives Tribes and the public a real opportunity to review the project and shape the issues the review covers.Why it holds +
The notice gives several ways to take part. There's a 45-day scoping period, planned meetings in Shungnak, Ambler, Kobuk and Fairbanks, a virtual meeting, and comments by the project website, email, mail or in person. It invites the Native Villages and cities of Ambler, Buckland, Deering, Kiana, Kivalina, Kobuk, Kotzebue, Noorvik, Selawik and Shungnak to act as cooperating and participating entities. It also commits to consultation under Executive Order 13175 and Section 106 of the National Historic Preservation Act. Some gaps remain. No in-person meetings are listed in Kivalina, Kotzebue, Noorvik, Selawik, Buckland, Deering or Kiana, and the meeting details are tentative and could change because of weather.
The agency says
“Scoping provides agencies, Tribes, stakeholders, and the public with an opportunity to review the proposed Project, understand the federal decision-making process, and provide input on the environmental issues that should be considered during preparation of the NEPA document.”
Scoping
Its own record backs it
“Given the remote nature of the Project area and the potential for weather-related travel disruptions in rural Alaska, meeting dates, times, locations, and virtual participation details remain subject to change.”
Scoping

How this was read

Read from the agency’s own notice ↗, all 32 pages. Every quote is checked word for word against it, a claim marked contradicted stands on a quote from the same document, and a second reading argued the agency’s side of every verdict before it was published. The verdicts are our reading; the quotes are the agency’s. A court can set aside agency action it finds “arbitrary, capricious, an abuse of discretion, or otherwise not in accordance with law” (5 U.S.C. 706(2)(A) ↗), which is why these gaps are worth putting in the record.

In the agency’s own words

Ambler Metals LLC proposes an open-pit copper, zinc and lead mine at the Arctic Deposit in the Ambler Mining District of northwestern Alaska, processing about 11,000 short tons of ore a day for about 13 years. The project would disturb about 1,727.2 acres, permanently fill about 120.7 acres of wetlands and other waters, store tailings behind an engineered dam at the headwaters of Subarctic Creek, and truck concentrate over the Ambler Access Project to Fairbanks. The U.S. Army Corps of Engineers, Alaska District, will prepare an EIS before deciding on a Clean Water Act Section 404 permit, and is taking scoping com…

Army Corps public notice ↗

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