Over 140 years since the Sunshine Mine opened in Kellogg, Idaho, Sunshine Silver Mining & Refining Co. completed its U.S. initial public offering on June 4, raising $270 million. 

Trading under the ticker symbol SSMR on the New York Stock Exchange, Sunshine Silver Mining sold 20 million shares at $13.50 each and will use the IPO proceeds for a planned restart of the historic Sunshine Mine, according to filings with the Securities and Exchange Commission. About $250 million will be used to fund feasibility studies, mining equipment, mine infrastructure purchases, mine development, overhead expenses, and exploration activities, SEC filings indicate. The company plans to be in production by 2028.

In a press release, Heather White, CEO of Sunshine Silver Mining, detailed the company’s debut and immediate goals.

“With our having a clear path to the revitalization and restart of the silver mine, Sunshine’s NYSE listing represents an important step as we move toward execution,” White says. “Our near-term focus is on completing infill drilling and engineering designs to support a feasibility study for the Sunshine Mine, currently targeted for completion in early 2027. From there, we plan to begin mill construction and complete infrastructure upgrades, with the goal of delivering silver production in late 2028.”

Sunshine Silver Mining & Refining Co. is a trade name for Silver Opportunity Partners LLC, a subsidiary of Electrum Group LLC, a New York-based investment company that acquired the Sunshine Mine property in 2010. According to the company’s website, it has invested over $200 million to expand its land position, modernize infrastructure, and deploy advanced exploration technologies to return the mine to production by 2028. The precious metals miner is an “emerging growth company” reporting a net loss of $34.7 million in 2025, compared to a net loss of $12.9 million in 2024, SEC filings show. The majority of those funds were used to ramp up operations, including expenses on predevelopment, exploration, and administration.

Following the IPO, the Electrum Group will retain a controlling stake in Sunshine Silver, holding about 61% of the company’s voting power, filings show. As a result, Sunshine qualifies as a “controlled company” under NYSE rules, allowing it to forgo certain corporate governance requirements applicable to other publicly traded companies.

After Sunshine Silver Mining raised a $270 million IPO, shares jumped 11% to $15.05 per share. Shares have fluctuated over the past two weeks between a low of $13.75 and a high of $17.15. As of Tuesday, June 16, shares of SSMR traded for $14.62.

Sunshine Silver Mining's corporate offices are located at 2209 Big Creek Road in Kellogg, Idaho, about 2 miles south of Interstate 90 and the Sunshine Mine Memorial. The Sunshine Complex includes the Sunshine Mine, a refinery, dubbed Sunshine Silver/Copper Refinery, and other facilities and storage buildings. It has a current staff of 95, filings show.

As previously reported by the Journal, North Idaho's silver mining corporations are expected to benefit from faster permitting and increased demand since the U.S. Geological Survey added silver to its 2025 List of Critical Minerals last year.

In the first quarter of 2026, the average price of silver increased 164% to $84.39, up from $31.91 per ounce in the year-earlier quarter, according to Coeur d’Alene-based Hecla Mining Co.’s first-quarter report. The value of silver as of June 16 was more than $70 per ounce.

The U.S. Geological Survey added silver, along with nine other minerals, to the critical minerals list in November 2025 due to its importance in the country’s technology and defense industries, the Journal reported. Minerals are considered critical if access to them is essential to the country’s economic health and national security. Silver is commonly used in the technology industry for its high thermal and electrical conductivity and is used in computer components, data centers, semiconductors, electric vehicles, antibacterial medical uses, and solar panels.

Once in production, the Sunshine Mine is expected to produce about 6.7 million ounces of silver annually in its first five years of production and 5.8 million ounces over a 24-year mine life, according to a company press release. At that level of production, Sunshine Mine would become the second largest primary silver mine in the U.S., the company claims.

Leadership at Sunshine Silver Mining say they believe that the mine has the potential to become a hub for critical minerals. Between 1953 and 2001, the mine produced over 48.4 million pounds of finished antimony, a silver-grey metalloid that is a critical material in manufacturing, defense, and renewable energy. The company currently is evaluating the design and engineering for the already-permitted Sunshine Antimony Plant, which is estimated to produce up to 34.5 million pounds of finished antimony annually, supplying up to 60% of U.S. demand, according to the release.

Sunshine had refined antimony for 65 years and was once the largest producer of the metal, especially during World War II, the Journal previously reported. Historically, Sunshine Mine has generated 92% of its revenue through silver production.

Dr. Thomas S. Kaplan, chairman of Sunshine Silver Mining, notes the importance of critical minerals with the current economic and geological landscape in the release.

“At the time when silver demand is rising across solar, electrification, electronics, and advanced technologies … Sunshine offers investors exposure to a scarce, U.S.-based pure-play silver asset,” Kaplan says. “With both metals (silver, antimony) having been declared to be critical minerals by both the United States and China, we believe this autonomy away from geopolitics to be a significant advantage.”

The Sunshine Mine was originally established in 1884 when brothers True and Dennis Blake filed the Yankee Lode claim, according to the company's website. 

While it was one of the most prolific mines in the world, it's also the site of one of the deadliest mining disasters in the U.S. In 1972, an underground fire broke out, and 91 trapped miners died from carbon monoxide poisoning. 

The mine ceased operations in the first quarter of 2001 due to the low price of silver and other operational factors, according to Sunshine Silver Mining's website. In 2003, it was acquired by Sterling Mining Co., which executed plans to bring the mine back into production. However, following a boardroom coup in 2008, the company eventually ceased production and declared bankruptcy in 2009, their website says.