Greens Creek: The Largest US Silver Mine, With Hecla's 2025 Output, Costs and Reserves

The largest US silver mine is Greens Creek, Hecla Mining's underground operation on Admiralty Island near Juneau, Alaska (Hecla 2025 Form 10-K). It produced 8.7 million ounces of silver in 2025. That ranked it 14th among the world's silver mines, ahead of the next U.S. entries, Red Dog (26th) and Rochester (27th), in the Survey's top 30 (Silver Institute, World Silver Survey 2026). This article sets out what Hecla's filings say about its output, costs and reserves.

Where it sits in U.S. supply

The World Silver Survey puts total U.S. mine output at 35.7 Moz in 2025, so Greens Creek alone supplied about a quarter of it (World Silver Survey 2026). The USGS reports that Alaska "continued as the country's leading silver-producing State, followed by Nevada," and that U.S. silver came from four silver mines plus 31 base- and precious-metal operations that produce it as a by-product (USGS Mineral Commodity Summaries 2026, silver). Silver was also added to the U.S. critical minerals list in November 2025 (USGS, iron ore chapter).

The mine

Hecla owns 100% of Greens Creek, which has produced since 1989 apart from a care-and-maintenance period from April 1993 to July 1996. The mine is reached by a ramp from surface and processes roughly 2,300 to 2,600 tons of ore a day. Concentrates ship from the Hawk Inlet marine terminal, about nine miles from the mill. The property sits within the Admiralty Island National Monument, which Hecla itself describes as "an environmentally sensitive area" (Hecla 10-K).

It is a polymetallic deposit: Hecla's reserve table carries silver, gold, lead and zinc, and the by-products matter to its economics (see below).

2025 production and costs

Sources: Hecla 2025 production release, Jan. 26, 2026; Hecla full-year 2025 results, Feb. 17, 2026.

Silver output rose 3% in 2025, mainly on a 5% improvement in grade, which more than made up for slightly lower throughput (Hecla, Jan. 26, 2026). The negative cost figures are the headline. The mine's gold, zinc and lead credits exceed its cash costs, so on Hecla's after-by-product measure each silver ounce costs less than nothing. Investors should read that as a sign of exposure to base-metal and gold prices, not as a sign that silver is free to mine. If zinc or gold prices fall, the credits shrink.

2026 so far

Greens Creek produced 4,228,164 oz of silver in the first half of 2026, slightly below 4,425,538 oz in the first half of 2025. It set a quarterly site free cash flow record of $130 million in Q2 2026 (Hecla Q2 2026 results, Aug. 4, 2026). In August, Hecla raised the mine's 2026 silver guidance to 8.0–8.3 Moz, up from 7.5–8.1 Moz, and guided AISC to between ($4.25) and ($3.75) per ounce. Its realized silver price was $63.06/oz in Q2 2026, against $73.14 for the first half (Hecla Q2 2026).

Reserves and growth options

At year-end 2025, Greens Creek's proven and probable reserves stood at 10.18 million tons grading 10.4 oz/ton silver, 0.083 oz/ton gold, 2.3% lead and 6.3% zinc. That is 106.1 million ounces of contained silver and 842,000 ounces of gold. The estimate uses $25/oz silver and $2,100/oz gold, well below 2026 realized prices (Hecla reserves release, Feb. 13, 2026). Hecla says the mine grew its reserve base by 2.4 Moz in 2025 even after a year of production.

As rough arithmetic of our own, not a Hecla mine-life estimate: at 2025's 79.3% silver recovery, the reserve would yield about 84 Moz, or roughly ten years at the 2025 production rate.

Hecla is also studying a pyrite concentrate circuit that could add about 1.0–1.2 Moz of silver and 10,000–15,000 oz of gold a year once ramped up. It estimates that the dry-stack tailings facility holds about 51 Moz of silver and 600,000 oz of gold (Hecla Q2 2026). Neither is a reserve. In January 2026 the U.S. Forest Service approved a five-year surface exploration plan for the property (Hecla reserves release).

What it means for investors

Greens Creek is Hecla's (NYSE: HL) largest silver source: 8.7 of the company's 17.0 Moz in 2025. Hecla's other U.S. mine is Lucky Friday in Idaho. The key risks are falling grades, by-product prices and operating within a national monument. The supports are a long reserve base and credits that kept its AISC below zero for full-year 2025 and for the first half of 2026 at ($9.52)/oz, though Q4 2025 was positive at $2.70 (Hecla Q2 2026).

For more coverage, see our silver hub, United States mining news and company profiles.

How we checked this: AI-drafted from the sources linked above and checked against them by our AI editor.