The Money What the Ambler Road costs, and who pays

REPORTING BY MORE THAN JUST PARKS
EVERY FIGURE HERE IS FROM AIDEA'S AUDITED FINANCIAL STATEMENTS FY2022 TO FY2025, TRILOGY METALS' FORM 10-K,
THE 2024 RECORD OF DECISION OR THE 2024 FINAL SEIS

What it costs, in the government's numbers

Item, Alternative A	Estimate
Road and associated facilities, construction	$672.4 million
Closure and reclamation	$77.7 million
Construction plus reclamation	$750.1 million
Annual maintenance	$11.9 million a year
Over the 50-year life AIDEA projects, maintenance alone	about $595 million, our multiplication

2024 Record of Decision, p. 23. 2024 Final SEIS, Vol. 1, p. 365, cost table by alternative. The 50-year multiplication is ours, undiscounted and in the review's dollars, which it escalated for inflation through the first half of 2023; the review does not state a life-cycle total. AIDEA's four most recent audited statements contain no projected construction cost for the road; the 2020 joint record's errata carried $501.9 million for the full road, and the estimates before that are charted in the precedents chapter.

What it costs today, with the interest

The federal estimate's highway prices stop at the end of 2022. Brought forward with the Federal Highway Administration's National Highway Construction Cost Index, the same index the estimate used, $672.4 million to build is about $763 million in 2026 prices, or $3.6 million a mile.

And AIDEA doesn't plan to pay cash. The plan in the federal review is 30-year revenue bonds, and AIDEA's own example in that review borrows at 5 percent. At that rate the interest on $763 million comes to about $726 million, close to what the road costs to build.

Over the road's 50-year life, our calculation	Estimate
Construction, in 2026 prices	about $763 million
Interest on 30-year bonds at 5 percent	about $726 million
Closure and reclamation, in 2026 prices	about $88 million
Maintenance, 50 years at the review's $11.9 million	about $595 million
Total	about $2.2 billion

Our calculation. Construction and reclamation: the 2024 Final SEIS figures (Vol. 1, p. C-3, whose footnote says its highway index ran "through end of 2022") times the FHWA National Highway Construction Cost Index, seasonally adjusted, 2022 Q4 to 2026 Q1 (2.7884 to 3.1655). Bonds: the SEIS, p. 3-206 and Table 18, AIDEA's example of 30-year bonds at 5 percent; AIDEA's stated range of 4.75 to 5.25 percent puts the interest between $684 million and $769 million. Undiscounted, the way the SEIS totals AIDEA's own example ($797.4 million repaid on $412 million). Maintenance is left in the review's dollars, so the total is the low end. Nothing is included for crossing NANA and Doyon land, because no agreement and no price exist.

And the estimate runs low against the state's own roads

Alaska's Department of Transportation has priced two other remote roads in the last fifteen years. Brought to 2026 prices with the same index, the road to Nome runs about $5.8 million to $7.5 million a mile, depending on width, and five routes for a West Susitna road run $7.9 million to $12.4 million a mile. Ambler's federal estimate is about $3.6 million a mile, for a road built wider than either. At the state's own rates, 211 miles would cost $1.2 billion to $2.6 billion to build, before a dollar of interest.

An independent estimate lands in the same place. Lois Epstein, an Alaska-licensed engineer, put the road's total at $2.03 billion in a January 2026 report released by the Alaska Wilderness League, using the same index and 4 percent bonds. AIDEA's executive director, Randy Ruaro, told the Anchorage Daily News, "They should wait until we get all the information and actually produce a very solid estimate before they start throwing numbers around." His authority's audited statements still carry no estimate at all.

Our calculation, each study's base-year average of the same index to 2026 Q1. Alaska DOT&PF, Western Alaska Access Planning Study, Corridor Staging and Alternatives Report, December 2011, Table 6: 548 miles, $1,279 million (24-foot) or $1,747 million (30-foot) plus $221 million in major bridges, 2011 dollars. Alaska DOT&PF, West Susitna Access Reconnaissance Study, January 2014, Tables 5-2 and 5-3: five 24-foot gravel routes, 33.5 to 107.9 miles, 2013 dollars. Ambler is two lanes and 32 feet wide at full build (2024 Final SEIS, ch. 2). Terrain and scope differ, and the West Susitna totals carry a 30 percent contingency and design costs that the federal Ambler table doesn't itemize, so the comparison is evidence the estimate runs low, not a replacement for it. Lois Epstein, P.E., LNE Engineering and Policy, "Estimating Ambler Road Construction, Maintenance, and Financing Costs," January 2026 (first-quarter 2025 dollars). Anchorage Daily News, March 9, 2026.

What the public has already put in

AIDEA is the Alaska Industrial Development and Export Authority, a public corporation of the State of Alaska, which means the money it spends is public money whether or not it passes through a legislative vote. So far: $17 million in direct appropriations; up to $35 million committed under 2020 funding agreements with Ambler Metals, by board action rather than a legislative appropriation; and $50 million authorised by its board on October 22, 2025, sixteen days after the presidential decision, for permitting, construction and legal costs. In fiscal 2025 the authority capitalised another $2.7 million of Ambler spending.

Building the road would take revenue bonds that AIDEA plans to sell to private investors, and the federal review's description of AIDEA's plan says those bonds "do not become a liability of the State." No buyer has been named, and the toll that would repay them doesn't exist. The public money already in is the $17 million the Legislature appropriated and what AIDEA has committed from its own funds.

AIDEA board resolution, October 2025, and audited financial statements FY2022 to FY2025 (Revolving Fund transfer, appropriations, FY2025 capital additions p. 19).

The toll that doesn't exist

The entire premise of the road is that mines pay tolls and the tolls repay the public. Here's how AIDEA's auditors explain why the authority hasn't booked a liability for the $20.7 million Ambler Metals has advanced:

"The parties have not entered into a road use agreement and the project has not advanced to construction, so it is not yet considered probable that a liability has been incurred." AIDEA audited financial statements, fiscal year 2025, p. 57

No agreement. Now the other side of the table. Trilogy Metals has booked the mineral reserve at Arctic, the only reserve in the district, on this assumption:

"The Mineral Reserve estimation assumes toll payments of $5.52/t processed, plus a road maintenance fee of $2.52/t milled processed, resulting in a total road toll and maintenance LOM unit cost of $8.04/t processed." Trilogy Metals Inc., Form 10-K, fiscal year ended November 30, 2025, p. 66

AIDEA FY2025 statements, p. 57 (no road use agreement) and p. 72 (the DeLong Mountain toll structure). Trilogy Metals Form 10-K, p. 66 (toll assumption) and p. 42 (transport cost of $270.98 per tonne of concentrate, the number that makes the 808-mile haul concrete).

Three documents, one gap. The company has told its investors what it expects to pay. The authority hasn't agreed what it will charge. And the authority's own pricing model needs a construction cost that the authority's own books don't contain.

The credits

Ambler Metals has been paying AIDEA's permitting and feasibility bills for years, and the money is described in the authority's statements as reimbursement. Read the next sentence:

"The agreement specifies that if the project proceeds to financing and construction, the parties have agreed that the amount advanced shall be converted by Ambler Metals into credits, which may be applied, with interest, to future user fees pursuant to any road use toll or similar agreement." AIDEA audited financial statements, fiscal year 2025, p. 57

So the money the mining company has put in is a prepayment on the tolls that are supposed to repay the public, it earns interest while it waits, and it doesn't appear on the authority's balance sheet as something owed. We state it in their words and leave the conclusion to the reader.

AIDEA FY2025 statements, p. 57; FY2024 statements, p. 63 ($19,487 thousand).

Nobody has a number that pays for the road

Put the question the simple way. The road is a public cost. What comes back to the public? Three documents hold the only answers anyone has produced: the first mine's own feasibility study, the state's federal review, and AIDEA's books. Set them in one column.

Public money, in and out	Figure	Whose number
Road toll and maintenance the Arctic mine assumes it would pay	$28.2 million a year	Trilogy's 2022 study, $8.04 a tonne
Over the mine's 13-year life	about $367 million	our multiplication
State revenue projected over the lives of all four mines	about $1.1 billion	the 2024 federal review
Local government revenue from the road itself	none expected	the 2024 federal review
Road construction, 2022 prices	$672.4 million	the 2024 federal review
Road over fifty years, with the bonds, upkeep and removal	about $2.2 billion	our calculation, above

Arctic Project S-K 1300 Technical Report Summary, November 30, 2022: p. 378, "This equates to an average road toll and maintenance cost of $28.2 M annually over the LOM, or $7.72/t milled over the LOM"; p. 221, the $8.04 assumption and its two warnings, quoted below. 2024 Final SEIS, Vol. 1, p. 269 ("approximately $1.1 billion over the lives of all four mines," about half of it from Arctic, 40 percent from Bornite, the rest from Sun and Smucker together) and the local revenue finding in this chapter's fourth finding. Road figures: the tables at the top of this chapter. Everything in this table is undiscounted, on both sides.

Two of the four mines in the state's $1.1 billion have never had an economic study. The third, Bornite, has a preliminary one, and the company's annual report says of it: "The financial model on which the analysis is based includes 100% inferred mineral resources. The results of the economic analysis excluding inferred mineral resources would not be economically viable." That leaves Arctic, the only reserve in the district, and Arctic's study says this about the toll it assumes:

"The amount paid in tolls by any user would be affected by the cost of the road, its financing structure, and the number of mines and other users of the road... There is a risk that a negotiated road toll agreement may result in higher costs than what has been assumed." Arctic Project S-K 1300 Technical Report Summary, November 30, 2022, p. 221

So the toll depends on the cost of the road, the cost of the road has no agreed figure, and the mine's reserve was booked on a toll nobody has agreed to. Each number leans on the next one.

What the mine is worth to its owners is a different question, and we don't mix them

The Arctic study puts the mine's after-tax value at $1,108 million, discounted at 8 percent, and its after-tax cash over the mine's life at $3,020 million undiscounted. Those are the owners' numbers, and on either footing the mine is worth more to its owners than the road costs. You'll see it claimed that "the metals are worth less than the road." They aren't, and setting a discounted mine value against an undiscounted road cost is the kind of arithmetic we'd call out in anyone else. The public's question is the table above: what comes back, against what goes out.

How often the base case is right

Every figure in that table is a base case produced by a party that gains if it's believed. The company's own record on its own mine is the best evidence of what base cases do. Trilogy has studied Arctic three times, in 2018, 2020 and 2022, on the same 10,000-tonne-a-day plant and the same 8 percent rate:

Arctic, the company's three studies	2018	2020	2022
Cost to build the mine	$779.6 million	$905.6 million	$1,176.8 million
Cost to close and reclaim it	$65.3 million	$205.4 million	$428.4 million
Copper price assumed	$3.00 a pound	$3.00 a pound	$3.65 a pound
Road toll and maintenance assumed, per tonne	$4.70	$8.04	$8.04
After-tax value at 8 percent	$1,412.7 million	$1,134.7 million	$1,108.1 million
After-tax rate of return	33.4 percent	27.1 percent	22.8 percent

Trilogy Metals, Arctic prefeasibility results, February 21, 2018 (Form 8-K, Exhibit 99.1). Trilogy Metals, Arctic feasibility results, August 20, 2020 (Form 8-K, Exhibit 99.1, Tables 2 and 3). Arctic Project S-K 1300 Technical Report Summary, November 30, 2022, p. 382 (capital, cash flow, NPV, IRR), p. 402 (metal prices), p. 221 (toll). All three on a 100 percent basis; Trilogy owns half. The 2022 report states its capital estimate's accuracy as plus or minus 15 percent in late-2022 dollars.

In four years the cost to build the mine rose 51 percent and the cost to close it rose more than six times, while the copper price the study assumed rose 22 percent. The after-tax value still fell by a fifth. The road's own estimate went from $300 million in the 2018 prefeasibility study to $672.4 million in the 2024 record, and to about $763 million in today's prices, before anyone has built a mile; the precedents chapter carries that ladder and the research on why estimates run this way. Nobody has a number that pays for this road, and the numbers that exist have moved in one direction every time anyone looked again.

Who gets paid, and who doesn't

The benefit case for the road is made in mine jobs and mine taxes. The road's own numbers, from the federal review, are smaller and more specific.

What the road itself produces	The record's figure
Direct construction jobs, whole construction phase	2,990, about 750 a year over four years
Of those, filled by residents of the Northwest Arctic and Yukon-Koyukuk region	about 120
Permanent operations and maintenance jobs	81, over an operating life of 44 to 46 years
Local government revenue from the road	None. "No local government revenues are expected to be generated during road construction, operation, or reclamation"
State revenue, if all four mines open and run their lives	about $1.1 billion, half from Arctic, 40 percent from Bornite

2024 Final SEIS, Vol. 1, p. 262 (local government revenue), p. 264 (construction jobs, 82 percent Alaskan, 120 regional), p. 269 (state revenue from four mines). 2024 Record of Decision, p. 27 (81 permanent jobs, 44 to 46 years). The four mines are the mines chapter; the record of decision says no plan for any of them is pending.

Who pays to take it down

The federal review estimates closure and reclamation at $77.7 million. The record of decision says AIDEA's proposal calls for removing the road at the end of its life "although no detailed reclamation plan has been developed," and records "uncertainty regarding the process of reclamation of the road, whether it would be successful, whether and how it would be funded and conducted." A full-text search of the joint record of decision for a reclamation bond, a performance bond, financial assurance or a surety finds no dollar amount anywhere.

This isn't a hypothetical. AIDEA's own 2017 review of its Red Dog road found, thirty-six years after it was built, that "the current agreements do not indicate the responsibility for any of the potential DMTS related DR&R," and its 2025 statements repeat that "neither the amount of potential costs nor the extent of the Authority's liability for DR&R is currently known." The state's mining reclamation bond pool, the last time a federal audit looked, held one million dollars and was priced for placer gold, not sulfide copper.

2024 Final SEIS, Vol. 1, p. 365. 2024 Record of Decision, reclamation. Joint Record of Decision, full text searched for "reclamation bond," "performance bond," "financial assurance" and "surety." AIDEA, DeLong Mountain Transportation System Asset Management Review, December 2017; FY2025 statements. GAO-05-377, June 2005, the bond pool figure as of July 2004, the most recent we hold; the precedents in full are here.

The part of the haul that's already free

The road is 211 miles. The trip to a port is 808 miles by the federal review's summary table and 936 in its route screening, which records AIDEA's reasoning: "the total distance to an existing port was noted as 936 miles, a high number but one that AIDEA appeared to be comfortable with and the majority of which (approximately 725 miles) would be utilizing existing transportation infrastructure." The Dalton, the Elliott and the Alaska Railroad. AIDEA would build and toll 211 miles, and the rest of the haul rides on the state-owned railroad and on highways the public already built, the Dalton alone maintained at about $16.5 million a year as of 2019. Industry pays no toll on those highways, and the state's own fiscal note says turning the Dalton into a toll road without adding new capacity would cost it its federal-aid eligibility.

2024 Final SEIS, Vol. 1, p. 573 (route screening) and p. 383 (808 miles); 2020 Final EIS, p. 265. Dalton maintenance and the failed 2026 toll bill: the precedents chapter. The two distances, 808 and 936, are different measures in different documents; we print both rather than average them.

Questions readers ask

How much would the Ambler Road cost?

The federal estimate is $672.4 million to build, $77.7 million to close and reclaim, and $11.9 million a year to maintain. Brought to 2026 prices with the Federal Highway Administration's construction cost index, construction is about $763 million.

AIDEA plans to pay for it with 30-year revenue bonds, and at the 5 percent in its own example the interest adds about $726 million. Construction, interest, fifty years of maintenance and removal come to about $2.2 billion, by our calculation. AIDEA's own audited statements state no total projected cost for the road anywhere.

2024 Final SEIS, p. C-3 and p. 3-206, Table 18; 2024 Record of Decision, p. 23; FHWA National Highway Construction Cost Index, 2026 Q1; our calculation, method on this page.

Who pays for the Ambler Road?

AIDEA, a state corporation, would build it with revenue bonds sold to private investors, and the plan is for mining companies to repay them through tolls. There's no toll agreement: AIDEA's auditors record, as of June 30, 2025, that "the parties have not entered into a road use agreement." Trilogy Metals has nonetheless booked its mineral reserve on an assumed toll of $8.04 a tonne.

The $20.7 million Ambler Metals has advanced for permitting converts, if the road is built, "into credits, which may be applied, with interest, to future user fees." If the road is built, the mining company gets that money back as credits against its own tolls.

AIDEA audited financial statements, FY2025, p. 57; Trilogy Metals Form 10-K, FY2025, p. 66.

Would the Ambler Road bring local government revenue?

The government's own review finds that "no local government revenues are expected to be generated during road construction, operation, or reclamation." The road itself supports 81 permanent jobs. Everything else in the benefit case is a mine, and no mine is permitted. The Case for the Road states the mine case as its supporters make it.

2024 Final SEIS, p. 262 and p. 264.

Do the mines pay for the Ambler Road?

Nobody has produced a number that does. The Arctic mine, the only one with a reserve, assumes in its own 2022 study a road toll and maintenance charge of $8.04 a tonne, about $28.2 million a year and about $367 million over its 13-year life, and no road use agreement exists. The 2024 federal review projects about $1.1 billion in state revenue over the lives of all four mines, two of which have no economic study; the third says it "would not be economically viable" without inferred resources. Against that, the road costs $672.4 million to build at 2022 prices and about $2.2 billion to carry over fifty years, by our calculation.

The mine is worth more than that to its owners (an after-tax value of $1,108 million at 8 percent in the company's study), and we don't set that discounted figure against the undiscounted road cost. The company's three studies of the mine also show what base cases do: the cost to build it rose 51 percent from 2018 to 2022 and the after-tax value fell by a fifth, while the copper price assumed rose.

Arctic Project S-K 1300 Technical Report Summary, Nov. 30, 2022, pp. 221, 378, 382, 402; Trilogy Metals Forms 8-K of Feb. 21, 2018 and Aug. 20, 2020, Ex. 99.1; Form 10-K FY2025 (Bornite); 2024 Final SEIS Vol. 1, p. 269; our calculation on this page.

How we know

AIDEA publishes audited financial statements every year and they're the most candid documents in this project, because auditors have to say why a liability isn't booked. We hold four years of them, alongside Trilogy's SEC filings and the federal decision documents, all searchable by passage in our record.

• AIDEA audited financial statements, FY2022, FY2023, FY2024, FY2025No road use agreement and the credits p. 57; DMTS toll structure p. 72; capital additions p. 19; DR&R liability
• Trilogy Metals Form 10-K, FY2025Toll assumption p. 66, transport cost p. 42
• 2024 Record of DecisionCost and maintenance p. 23, jobs p. 27, reclamation
• 2024 Final SEIS, Volume 1Cost table p. 365, jobs p. 264, local revenue p. 262, state revenue p. 269, route screening p. 573
• AIDEA, DMTS Asset Management Review, December 2017The guarantee, and the unassigned removal cost
• GAO-05-377, June 2005Alaska's reclamation bond pool