United Keno Hill Mines Reclamation Project

On this page

• History of United Keno Hill Mines
• Responsible parties
• United Keno Hill Mines reclamation activities
• Reclamation plan
• Progress to date
• Next steps
• Contracting and jobs
• Contact us

History of United Keno Hill

The United Keno Hill Mines are a collection of more than 50 individual silver mines in central Yukon, 55 kilometres northeast of Mayo and within the Traditional Territory of the First Nation of Na-Cho Nyäk Dun. The site extends over 15,000 hectares in size, with approximately 500 hectares of land impacted by historic mining activity. Water from the site flows to the South McQuesten and Keno Ladue River basins.

The area supported traditional practices before mining and many First Nation of Na-Cho Nyäk Dun citizens were involved in supporting mining operations. Oral history accounts describe travel routes, hunting and fishing and traditional activities in the area now known as Keno Hill.

The United Keno Hill Mines properties produced 200 million ounces of silver from 1931 to 1989. A mill operated at Wernecke Camp from 1925 to 1931. A larger mill, built in Elsa in 1936 and replaced in 1949 after a fire, processed ore from mines on Galena Hill including the Hector-Calumet and Elsa mines. Open pit and underground mining in the Keno Hill area produced:

• 4.8 million tonnes of ore
• approximately 4.6 million tonnes of tailings
• 4.75 million tonnes of waste rock

The main environmental concerns on site are elevated cadmium and zinc levels observed in soils and water in some locations at the site.

The Hector mine, largest in the district, was abandoned in 1972, while production continued at the Husky Mine until 1989. The United Keno Hill Mines site was declared abandoned in the early 2000s and is currently in active reclamation.

Responsible parties

The Government of Canada initially assumed responsibility for care and maintenance of the United Keno Hill Mines site after declaring it abandoned in 2001.

The abandoned United Keno Hill Mines was then designated as a Type roman numeral 2II Site under the Yukon Northern Affairs Program Devolution Transfer Agreement (Devolution Transfer Agreement) on April 1, 2003. Under this agreement, the Government of Canada is responsible for pre-2003 environmental liabilities and costs of reclamation for abandoned Type roman numeral 2II mine sites. Responsibility for addressing the sites is shared between the Government of Canada and the Government of Yukon, working with Affected First Nations. The agreement identifies the First Nation of Na-Cho Nyäk Dun as an Affected First Nation for the United Keno Hill Mines site.

Following a brief period where the site was owned by a mining company, the site was declared abandoned a second time in 2003 by the Government of Yukon, which now assumed responsibility for care and maintenance of the site.

In 2006, following a commercial sale process, Alexco Resources Corporation (Alexco) purchased the United Keno Hill Mines site. The Government of Canada then entered into a commercial agreement with Alexco and their wholly owned subsidiary the Elsa Reclamation Development Company (ERDC) to perform ongoing environmental care and maintenance associated with the historic United Keno Hills Mines site, and to develop and implement a Reclamation Plan for the site to address historic liabilities. Under the agreement, ERDC is responsible for ensuring that the site remains in compliance with the terms and conditions of the water licence and all applicable environmental laws.

The commercial agreement also allows the company to undertake exploration and active mining at the United Keno Hills Mines site. When ore begins to be produced from a site for commercial purposes, a Production Unit is negotiated that transfers the land and reclamation obligations to the company. Production Unit boundaries provide clear and logical differentiation between past and current/future mining activities and reclamation obligations.

In 2022, Hecla Mining Company (Hecla) acquired Alexco and, along with ownership of the United Keno Hill Mines site, also assumed care and maintenance and reclamation responsibilities for historical liabilities.

Through the Northern Abandoned Mine Reclamation Program, the Government of Canada maintains oversight of the project and funds:

• care and maintenance
• site monitoring
• reclamation planning and implementation

Work on the reclamation project by the governments of Canada and Yukon is done in consultation with the First Nation of Na-Cho Nyäk Dun. This collaborative approach to reclamation, along with benefits and opportunities from reclamation of the site (and around active mining too), demonstrates progress toward reconciliation.

United Keno Hill Mines reclamation activities

Prior to 2023, activities on site were limited to care and maintenance activities including maintaining site infrastructure such as:

• buildings
• roads
• water treatment infrastructure
• ensuring site safety
• treating contaminated water draining from several underground mine entrances (adits)

In 2023, ERDC obtained a water use license for active reclamation, and in 2024, active reclamation of the site began. The first task was to rehabilitate mine entrances and tunnels where contaminated water will be collected before going to a centralized water treatment plant. Pipeline corridors for moving water to the water treatment plant and rough grading of the water treatment plant site were also completed in 2024.

In 2025, ERDC continued to advance active reclamation of the site, starting the construction of the centralized water treatment plant, completing construction of the tailings facility water treatment plant, relocation and consolidation of tailings and completing additional rehabilitation work on mine entrances and tunnels.

Reclamation plan

Reclamation plan development started in 2008. The project's objective is to transition the abandoned mine site to a reclaimed mine site with minimal post-reclamation care and maintenance, while reducing the long-term environmental, health, and safety risks associated with the site.

The United Keno Hill Mines Reclamation Project proposal was submitted to the Yukon Environmental and Socio-economic Assessment Board (Project #2018-0169) in 2018 by the ERDC and, following the completion of the review and reporting process, was allowed to proceed in 2020.

Planned reclamation activities include both conventional lime water treatment, as well as in situ water treatment technologies for historic underground drainage waters. The potential physical and safety risks on site will be reduced by closing and capping open shafts and blocking underground mine entrances (adits) with rock piles or constructed bulkheads that allow the drainage to be controlled and routed to water treatment facilities.

The reclamation plan also includes relocation and consolidation of tailings from several locations to reduce metals leaching to the downstream environment, and stabilizing or removing tailings dams.

Reclamation activities for open pits and waste rock storage areas include safety berms, diversions, regrading of slopes, and soil covers.

Progress to date

Timeline of events and progress to date:

Consult the Hecla Mining Company website for additional information and updates.

Next steps

Active reclamation is expected to take 5 years to complete, followed by a transition period during which the effectiveness of the reclamation activities will be confirmed.

Ongoing water treatment and periodic maintenance are expected to continue.

Contracting and jobs

Work associated with the United Keno Hill Mines Reclamation Project is being contracted by the owner of the site.

Consult the Hecla Mining Company website for information on contracting and job opportunities.

Contact us

United Keno Hill Mines Reclamation Project
415C-300 Main Street
Whitehorse, Yukon
Y1A 2B5
1-800-661-0451
Email: YTcontaminatedsites-sitescontaminesYT@rcaanc-cirnac.gc.ca