Hecla Greens Creek Mine: Output, Reserves, Mine Life

Hecla Greens Creek mine at a glance

Greens Creek is an underground silver, gold, zinc and lead mine on Admiralty Island, about 18 miles southwest of Juneau, Alaska. It is owned 100% by Hecla Mining Company (NYSE: HL) and produced 8.7 million ounces of silver and 59,349 ounces of gold in 2025 (Hecla fourth-quarter 2025 results). Hecla describes it as the largest silver mine in the United States, and the Alaska Division of Mining, Land and Water says it has run since 1989, around the clock, every day of the year (Alaska DNR).

This page collects the numbers people search for: output by year, reserves and resources, costs, expected mine life, and the environmental and community record. Every figure carries its source and date. Apart from Hecla’s quarterly average prices in the cost section, this page gives no silver or gold price; the calculator lets you enter today’s price.

The property sits inside a federally protected monument, but outside the Kootznoowoo Wilderness area. Hecla states that more than 955,000 acres of Admiralty Island are designated as a national monument and that the mine lies on the northwest end, outside the 936,649-acre wilderness. Hecla’s general manager told Alaska Business Magazine in 2020 that it is the only US mine permitted to operate inside a national monument (Alaska Business Magazine, April 2020). That position is why the permits, monitoring and reclamation bonds described below get so much attention.

How much silver does Greens Creek produce each year

Output has stayed in a band of roughly 8 to 10 million ounces of silver a year. The mine processed 846,076 tons of ore in 2019 and produced 9.9 million ounces of silver (Alaska Business Magazine, April 2020). Alaska DNR lists about 9.7 million ounces of silver, 60,900 ounces of gold, 51,500 tons of zinc and 19,600 tons of lead for 2023.

Chart

Greens Creek silver output by quarter

Million troy ounces of silver

Hecla’s results show 8,480,877 ounces of silver and 55,275 ounces of gold in 2024, then 8,724,996 ounces and 59,349 ounces in 2025. In 2025 the mine also produced 18.2 thousand tons of lead and 51.3 thousand tons of zinc (Hecla operations page). For 2026 Hecla guided to 7.5 to 8.1 million ounces of silver and 51,000 to 55,000 ounces of gold in January. Its second-quarter 2026 release raised the 2026 silver outlook for Greens Creek to 8.0 to 8.3 million ounces (gold unchanged at 51,000 to 55,000 ounces), and the first half of 2026 produced 4,228,164 ounces of silver, against 4,425,538 ounces in the first half of 2025 (Hecla second-quarter 2026 results).

Output moves with the grade of the ore being mined, so quarters differ by as much as 24%. The fourth quarter of 2025 was the lowest of that year at 1.95 million ounces, and the second quarter of 2025 the highest at 2.42 million ounces.

Where Greens Creek ranks among the world’s silver mines

The Silver Institute’s World Silver Survey 2026 puts Greens Creek 14th in the world by 2025 silver output, at 8.7 million ounces, up 3% on 2024 (Silver Institute, World Silver Survey 2026). Most of the larger silver producers are mines where silver is a by-product of copper, lead-zinc or gold. Greens Creek sells silver, zinc, gold and lead together, so it is called a polymetallic mine.

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Silver output at Hecla’s three silver mines

Million troy ounces of silver

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Silver output at selected mines, 2025

Million troy ounces of silver, 2025

The US Geological Survey reports that US mines produced about 1,100 tons of silver in 2025, that Alaska was the leading silver-producing state, and that Nevada was second (USGS Mineral Commodity Summaries 2026). Hecla’s own total from Greens Creek, Lucky Friday in Idaho and Keno Hill in Yukon was 17.0 million ounces in 2025. For a broader list of producers, see our comparison of the top silver producing companies.

Related reading on this site: Boddington Mine WA: Output, Reserves and Mine Life.

We cover a connected topic in Porgera Gold Mine: Owners, Output, Reserves and Impacts.

Greens Creek mine reserves and resources

A mineral reserve is the part of a deposit that a qualified person judges can be mined at a profit with today’s costs and prices. A resource is a wider estimate with less certainty, and Hecla reports its resources in addition to its reserves. At 31 December 2025 Hecla reported the following for Greens Creek (Hecla reserves and resources table).

The reserves also hold about 238,000 tons of lead and 638,000 tons of zinc. Hecla used a silver price of US$25 an ounce and a gold price of US$2,100 an ounce for the reserves, and a net smelter return (NSR) cut-off of US$275 a ton. NSR is the value of the metals in a ton of ore after smelter charges and losses; ore below the cut-off does not pay for mining and processing. Resources use US$26 silver and US$2,250 gold. Recoveries actually achieved in 2025 were 79.3% for silver, 74% for gold, 82.6% for lead and 88.8% for zinc, which is why the calculator below applies a recovery rate.

The proven category is tiny: 13,000 tons of surface stockpile at 23.93 oz/ton silver. Almost everything in the reserves is probable, meaning it rests on indicated resources. Grades are in ounces per short ton, so 10.42 oz/ton is about 357 grams of silver per metric tonne.

What it costs to run: why the silver cost is below zero

Hecla reports cash cost and all-in sustaining cost (AISC) for Greens Creek after by-product credits. That means the cost of mining and milling the ore, minus the money from the gold, lead and zinc sold with the silver, divided by the silver ounces. When by-product revenue is larger than the cost, the result is negative. It does not mean that silver costs nothing to produce; it means gold and base metals pay for the mine.

In 2025 Greens Creek had a total cost of sales of US$290 million, a silver cash cost of minus US$8.02 an ounce and an AISC of minus US$2.36 an ounce. In the second quarter of 2026, costs applicable to sales were US$50 million, with a silver cash cost of minus US$17.11 and an AISC of minus US$10.71 an ounce. The average London silver fix that quarter was US$73.44 an ounce and gold averaged US$4,517 (Hecla second-quarter 2026 results). Hecla also reported a record quarterly site-level cash flow after capital spending of US$130 million. Higher prices lift the by-product credit, so the cost line is sensitive to the gold price as well as the silver price.

For 2026, Hecla’s January guidance had a total cost of sales of US$287 million and sustaining capital of US$66 to US$71 million at Greens Creek, much of it for mine development and the tailings facility expansion.

Calculator: what a year of milling is worth

Use the calculator below to test how tonnes, grade, recovery and price combine. The defaults are round example numbers, not Hecla figures; the reserve grades and 2025 recoveries in the table above are a better starting point for a scenario.

How long will Greens Creek keep operating

There is no published closure date. Mine life depends on tailings space, reserves and permits, and the three have moved together. On 7 November 2024 the US Forest Service permitted an expansion of the tailings facility that could extend operations by up to 18 more years, with production continuing past 2031 until at least 2043 (Juneau Empire; KTOO / Alaska Public Media, 8 November 2024). Hecla says the expansion, when complete, should provide tailings storage capacity through 2045 (Hecla, fourth-quarter 2025 results).

The same coverage reports new conditions that come with the approval: a plan to cut fugitive dust from the tailings piles, including misting and reducing exposed tailings in winter, Forest Service measurement of dust, and a collaborative monitoring panel with the Forest Service, Hecla, state and federal agencies, and representatives of Angoon and Kootznoowoo, Inc. In early 2026 Hecla also received a finding of no significant impact and a decision authorizing surface exploration.

Two growth ideas are under study, both aimed at metal already at the site:

• Pyrite concentrate circuit. Preliminary work points to 1.0 to 1.2 million ounces of extra silver and 10,000 to 15,000 ounces of extra gold a year at full ramp-up. Hecla targets first production between the fourth quarter of 2027 and the first half of 2028, subject to permits and final investment approval.
• Tailings reprocessing. At 30 June 2026 the dry stack held an estimated 10.6 million tons of material with about 51 million ounces of silver and nearly 600,000 ounces of gold. Hecla calls the project conceptual, with a third-party metallurgical study (Phase 3 testing was scheduled to finish in August 2026), and says processing costs are expected to be significant.

These are company plans at an early engineering stage, not approved projects. Treat them as possibilities.

Environmental controls at the mine

The mine’s reputation depends on how it handles water, tailings, power and closure. These are the controls Hecla and the regulators describe, each with a source and a date.

Infographic

How Greens Creek handles tailings

1. 1Mill the oreFlotation and gravity processing recover silver, gold, lead and zinc.
2. 2Press the tailingsFilter presses squeeze out water to leave a low-moisture solid.
3. 3Backfill undergroundIn 2025, 54% of tailings went back into mined-out areas.
4. 4Stack the rest dryThe remainder is trucked to a dry stack that does not dam water.
5. 5Monitor and reclaimDust, water and fish are monitored; bonds fund closure work.

1. Dry-stack tailings

Tailings are the fine ground rock left after the metals are removed. At Greens Creek they are filter-pressed to a low moisture content and trucked to a pile that does not dam water. Hecla says this keeps the surface footprint small and lowers the consequences of a failure (Hecla operations page).

2. Backfill underground

In 2025 the mine returned 54% of its tailings underground as backfill rather than sending them to the dry stack, which cuts surface storage and adds stability to the mine workings (Hecla, 2025 data).

3. Treated discharge to Hawk Inlet

Treated water is discharged into Hawk Inlet under state and federal permits. Hecla works with the Alaska Department of Fish and Game on annual freshwater surveys of salmon and trout, their food and habitat, and added new monitoring points under the November 2024 decision. The Alaska DNR page lists the water-rights certificates and amended water permits for the site, with the most recent dated October 2025.

4. Hydropower first

Greens Creek buys surplus hydropower from the Juneau grid when it is available. In 2025 low rainfall reduced the supply and 62% of the mine’s electricity came from the grid. Hecla says the arrangement has avoided more than 90 million gallons of diesel since 2009. Diesel generators remain as backup (Hecla operations page and Alaska DNR, 2026).

5. Dust control

The 2024 approval requires a fugitive dust plan, because waste rock is stored on the surface temporarily and fine particles can blow off into forest and waterways. The Forest Service has committed to measure dust to check that the controls work (KTOO, November 2024).

6. Reclamation bonds

Hecla must return the site to a natural state after mining: remove structures, regrade and seed the land, monitor the tailings facility and monitor water quality. It reports bonds of US$92.17 million, including US$16 million for a trust that would pay for long-term water monitoring and treatment, held by the US Forest Service and the State of Alaska. Alaska DNR approved a reclamation plan on 14 September 2026.

7. A community advisory group

Hecla set up the Greens Creek Community Advisory Group, with members from the Alaska Native community, local government, business, education and environmental groups, so that community input reaches mine planning (Hecla operations page, 2026).

What is not in this list: hectares restored, percentage reductions in emissions and satisfaction scores. Hecla’s pages and the regulators’ pages do not give those numbers for this mine in the form often quoted online, so they are left out.

▶ Our short claymation on the seven environmental impacts of mining, and how they are managed. · 2:31

Jobs and money in Juneau

Hecla states that it is the largest private-sector employer and taxpayer in Juneau, with about 540 direct jobs; Alaska DNR gave about 512 employees in 2024. Hecla reports more than US$97 million in wages in 2025, and a 2020 interview with the general manager put local purchasing at about US$58 million a year at that time. The mine’s surplus-power deal with the local utility has helped lower electricity rates for Juneau residents, according to Hecla.

The mine also funds student aid at the University of Alaska Southeast, with more than US$1.8 million since 2011 (Hecla operations page, 2026), and an earlier training partnership of about US$1 million for a mine diesel mechanic programme (Alaska Business Magazine, 2020).

▶ Our explainer on what mining contributes to an economy: exports, jobs and revenue. · 5:03

Watching a remote mine from space

Greens Creek is reached only by sea, in dense forest. Satellite imagery is useful here for the questions regulators and companies ask about a site like this: how big the cleared and stacked area is, how it changes season to season, and whether vegetation on regraded ground is recovering. Clouds limit the number of clear Sentinel-2 scenes, so the picture at the top of this page is a summer composite built from several dates.

Farmonaut is a US-based company that produces satellite-based mineral detection reports for teams that want to screen large areas before field crews deploy. You can send a request for your own project area or read about satellite mineral detection. Farmonaut has no connection with Hecla or the Greens Creek operation.

▶ Remote sensing for mining explained in about two minutes. · 2:01

Frequently asked questions

Who owns the Greens Creek mine?

Hecla Mining Company owns 100% through Hecla Greens Creek Mining Company. When production began in 1989 Hecla owned almost 30%, and it bought the remaining interest from Rio Tinto subsidiaries in 2008 (Alaska Business Magazine, 2020).

Where is Greens Creek mine?

On Admiralty Island in southeast Alaska, about 18 miles southwest of Juneau and 40 miles north of Angoon, near Hawk Inlet. It is reached by sea (Hecla and Alaska DNR).

How much silver does Greens Creek produce?

It produced 8.72 million ounces in 2025 and 8.48 million ounces in 2024. Hecla’s January 2026 guidance was 7.5 to 8.1 million ounces, raised in August 2026 to 8.0 to 8.3 million ounces.

What are the Greens Creek reserves?

Proven and probable reserves at 31 December 2025 were 10.18 million short tons containing 106.1 million ounces of silver and 842,000 ounces of gold, plus lead and zinc (Hecla).

Is Greens Creek the largest silver mine in the United States?

Hecla describes it that way, and the USGS reports that Alaska is the leading silver-producing state. Worldwide it ranked 14th in the Silver Institute’s 2025 list.

How long will Greens Creek operate?

No closure date is published. The 2024 Forest Service approval of the tailings expansion could extend operations by up to 18 years, and Hecla says the expanded facility provides capacity through 2045.

How many people work at Greens Creek?

About 540 direct jobs according to Hecla in 2026; Alaska DNR gave about 512 in 2024.

Why is the cost of silver at Greens Creek negative?

Because Hecla subtracts revenue from gold, lead and zinc, the by-products, from the cost of mining before dividing by silver ounces.

Is Greens Creek mine really inside a national monument?

Yes. It lies within the Admiralty Island National Monument but outside the Kootznoowoo Wilderness area, on 17 patented lode claims and one patented mill site claim (Hecla).

Can I visit Greens Creek?

The mine is an operating industrial site on Admiralty Island, reached by sea, so access is controlled by the operator. Ask Hecla through its website if you have a business reason to visit.

Not investment advice. Hecla figures are the company’s own reported numbers, cited to the release or page named.