ODDS’N’SODS — The saga of the Granduc mine

I will never forget the day in 1978 when Treavor Hancock, supervisor of British Columbia’s Granduc copper mine, phoned to tell me that the roof of the mill had collapsed under the weight of ice and snow.

I was the district inspector of mines at the time, and he asked me to survey the damage. The scene was sad indeed; most of the plant, including the main operations, had been buried under the mass. It had just previously been decided to close down the mine. Maintaining the heating plant was deemed too expensive, and the power plant and mill had been left, in a region of heavy snowfall, to the elements.

The distressing site of the collapsed mill induced me to replay, in my mind, the story of how the Granduc mine came to be.

In 1946, I met Einan Quale and Tom McQuillan (two prospectors sent in by minefinder Karl Springer) pulling their toboggan up the North Leduc glacier.

They staked claims on Granduc Mountain for Springer and his company, Helicopter Exploration. The saga of the Granduc mine began in the early 1950s when the Granby Mining Company, under Larry Postle, conducted an extensive exploration and development program. The survey employed helicopters and tractor trains, and camps and landing strips were built on glaciers. Granby was later joined by Newmont Mining Corp. Extensive underground work and the sinking of an internal shaft established a preliminary reserve of 32.5 million tons at 1.9% copper — more than 1 billion lb. copper within 25 miles of tidewater.

A feasibility study, undertaken in the early 1960s, deemed it economic and viable to establish a mine, plant and mill at Tide Lake. The complex was to be connected to the mine at Leduc by a 10-mile-long tunnel. A road stretching 25 miles from Stewart would provide access to the Tide Lake site, and a dock for concentrators and supplies of heavy-oil fuel would be built at Hyder, Alaska. The total cost of the project was estimated at $55 million.

In order to facilitate the financing, Newmont entered into a partnership with Hecla Mining Company. Another backer, the American Mining and Smelting Company, would provide for the marketing of the copper concentrates with advance loans. At this time, Merv Upham and Nick Gritzuk were hired as Granduc’s managers.

By June 1964, the financing was in place and road construction in the Salmon River Valley began. The road ran past the Premier mine, into the shadow of the Salmon glacier and on to Tide Lake. In concert with this development, two camps were set up. One was erected at the proposed mill site at Tide Lake and another, named the Portal camp, at the Leduc minesite. From these two bases, the tunnel would be advanced from both ends. Tunnel driving began in September 1964, though further progress was halted following an avalanche that hit the Portal camp on Feb. 18, 1965. Twenty-six lives were lost and the facility destroyed.

A new study was commissioned, but the basics of the project remained the same. By this time, ore reserves there were estimated at 43.3 million tons grading 1.73% copper. The new study put the cost of the project at more than $100 million and, as a result, the Granduc Operating Company entered a partnership with Newmont and American Smelting and Refining.

The driving of the tunnel resumed in June 1965, and 54,518 ft. were completed by December 1968. Considering the remoteness of the site, the extremes of the weather, the forbidding enclosures of the mountains and glaciers, as well as the weak ground conditions encountered in some sections of the tunnel, this was indeed an achievement without equal.

Site preparations and construction of the mill began at Tide Lake in November 1970. In January 1971, the first shipload of copper concentrate from the Granduc mine left Stewart for Japan.

Operations were halted for a time, but in 1978 the mineral exploration end of Esso acquired the mine and proceeded to rehabilitate the plant and place it back in production. The operation shut down again in 1986.

Today, the site at Tide Lake is a tourist attraction visited by people impressed by the grandeur of the Little Salmon and Berenden glaciers. In my heart and mind, the Granduc mine remains forever a reflection of the toil, dedication and devotion of the many people who struggled with adverse elements to achieve a spectacular success.

— The author, a retired mining engineer, resides in Vancouver, B.C.