Coeur Investments: Kensington Mine readies for tailings expansion.

• Author: O'Hanley, Tara

Above the northwest side of Berner's Bay and at the foot of Lion's Head Mountain in the Tongass National Forest, 45 miles north-northwest of Juneau, Coeur Alaska's Kensington Mine has grown to become the second-largest private employer in Southeast since it began operations in 2010.

Coeur Alaska's parent company, Chicago-based Coeur Mining, is a well-diversified and growing precious metals producer. In addition to Kensington, it also operates mines in Nevada, South Dakota, and northern Mexico, as well as an exploration project in British Columbia. But the company says it is "all in" on Alaska.

Coeur's 2022 annual report states the company has invested approximately $245 million in exploration, leading to increases of approximately 21 percent and 49 percent in company-wide gold and silver reserves, respectively, over the five-year period.

These investments are already paying off in Alaska, too. Coeur's year-end 2022 Mineral Reserves and Resources report noted a 56 percent year-over-year increase in Kensington's gold reserves: geologists identified several areas with highgrade gold mineralization that could potentially support new mining operations, adding 1.5 years to the life of the Kensington Mine. "That's the first time since 2017 that we've had an increase in reserves and only the second time since modern mining started in Kensington, when we began commercial production in 2010," says Stephen Ball, the mine's general manager.

In 2022, Coeur Alaska received a final record of decision from the US Forest Service for its Plan of Operations Amendment 1 (POA 1). Coeur Alaska has been undergoing a permitting process to expand waste rock and tailings storage capacity to reflect its positive exploration results and continuous operational improvements. "Getting the increase of reserves was an important milestone to continue with our multi-year drilling and development plan," says Ball. "It required a bit of forethought with the permitting, as we needed the additional storage capacity before we could push an aggressive exploration program to build additional reserves."

Under the approved plan, Coeur intends to raise the height of Kensington's existing tailings dam by 36 feet, which would increase tailings storage capacity by an additional 4 million tons. The company will also construct a 40-foot "back dam" between the Lower Slate Lake tailings treatment facility and Upper Slate Lake, as well as expand three existing waste rock storage facilities...