History of Giant Mine

Gold Stakes & Bricks

Gold was first discovered in the Yellowknife area by prospectors heading North to get a piece of the Klondike riches in 1896. Nothing came of the Yellowknife discovery at the time because the area was considered inaccessible. By 1935 however, the eager prospectors were back, hunting the yellow rock all along the northern shores of Great Slave Lake. The arrival of commercial aircraft (bush planes) made the area more accessible.

One of the richest gold mines ever found in Canada occurred along the Great Slave Lake's beautiful Back Bay and along what is now the historic Ingraham Trail. In the summer of 1935, C.J. "Johnny" Baker and H. Muir staked the original 21 "Giant" claims for Bear Exploration Company. Those claims led to the production of seven million ounces of gold and resulted in one of the longest continuous gold mining operations in Canadian mining history.

According to historical accounts from the Yellowknives Dene First Nation, Liza Crookedhand, an elder woman who camped every year at the Wildeh (Yellowknife River), played an integral part in the gold discovery around Yellowknife. (The Giant Gold Mine – Our Story: Impact of the Yellowknife Giant Gold Mine on the Yellowknives Dene - A Traditional Knowledge Report (YKDFNLEC, 2005)  ).

Historical Timeline from 1935-2013

By 1937, Yellowknife Gold Mines Ltd. had acquired Burwash's assets and created the subsidiary Giant Yellowknife Gold Mines Ltd. The company fell on hard times and by 1940, operations eventually came to a standstill at the site. Frobisher Explorations took over the site in 1943, after D.W. Cameron reported promising findings. However, the advent of World War II halted the operation as gold was not deemed to be a strategic priority, and there was a shortage of men to work the site.

Soon after the war ended, Giant Mine officially opened and production moved into full swing. The first gold brick was poured on June 3, 1948. From May to December 1948, the mine produced 8,152 ounces of gold from 49,985 tonnes of ore. With the nearby Con Mine also in full operation, Yellowknife was experiencing a rapid growth due to the available number of jobs and associated economic benefits of the booming mining industry.

An old photo of the buildings, with the headframe in the centre, at the Giant Mine site in Yellowknife.

Making the Gold — and the Arsenic Trioxide Waste

Gold at Giant Mine is found in specific minerals - arsenopyrite ore. To release the gold, the ore had to be roasted at extremely high temperatures. Unfortunately, this roasting process also released arsenic rich gas, a highly toxic by-product.

In the early days, much of that arsenic was released directly into the environment via the stack. This situation was quickly rectified in 1951, by installing a Cold Cottrell Electrostatic Precipitator (ESP), which removed a lot of the arsenic trioxide waste that formed when the cooling roaster gas combined with oxygen.

Arsenic releases were reduced to 2,900 kilograms a day in 1956, down from 7,400 kilograms a day in 1951. Another innovation was added to the site in 1958 - a Dracco baghouse - which did a better job of collecting the waste and reduced airborne arsenic emissions to 52 kg/day by 1959.

Over the years, that number would fluctuate up to 300 kg/day. A Hot Cottrell ESP was also added to the roasting process, which assisted in further reducing emissions.

Giant Mine was in full operation for about 50 years, and during this time the mine produced 237,000 tonnes of arsenic trioxide waste.

In the 1950s, scientists and government agencies agreed that storing the waste in underground stopes and chambers was an appropriate, long-term alternative. It was believed that when Giant Mine closed permanently, the natural permafrost in that area would re-establish around the storage vaults and seal in the arsenic trioxide.

In the 1980s, Koppers Corp. of Pittsburgh, Pa. purchased 6,700 tonnes of crude arsenic trioxide waste from Giant Mine for treating wood. However, the vast majority of the arsenic trioxide created during production still remains underground at the site.

Ownership of Giant Mine

Giant Mine was owned by several companies over the years. In 1990, Royal Oak Resources Ltd. purchased Giant Mine, and formed Royal Oak Mines Inc. In May 1992, local branch of the Canadian Association of Smelter and Allied Workers at Giant Mine (which eventually joined the Canadian Auto Workers) went on strike. In September of that year, during ongoing labour unrest, a deliberately-set explosion underground killed nine miners. The striking miners eventually returned to work in December 1993.

In 1997, officials with Aboriginal Affairs and Northern Development Canada (AANDC) met with Royal Oak Mines Inc., Environment Canada, the Government of the Northwest Territories, and the City of Yellowknife to hold a technical workshop to discuss the management of the arsenic trioxide waste stored underground at Giant Mine. Two years later, Royal Oak Mines Inc. went into receivership. The courts transferred Giant Mine to AANDC.

Shortly afterwards, AANDC sold the mine's assets to Miramar Giant Mine Ltd., a division of Miramar Mining Corporation. The sale was conducted to ensure the maximum number of jobs would continue at the mine and that a knowledgeable, experienced operator would oversee the care and maintenance of the site. As a condition of the sale, AANDC acknowledged that Miramar would not be responsible or liable for the existing state of the mine, including the arsenic trioxide stored underground. AANDC was assigned a caretaker role for the existing conditions at the site, including the arsenic trioxide waste stored underground.

The ore at Giant Mine was no longer processed after 1999. Miramar Giant Mine Ltd. terminated its obligations under the Reclamation Security Agreement in 2005 and Giant Mine officially became an abandoned mine site.

The Golden Touch

When C.J. "Johnny" Baker was out working on the newly staked rich claim at Burwash Point one day, something odd caught his eye. He was standing on Burwash Point, across the lake from what is now the Giant Mine site. He was standing by the mineralization streak in the rock that had lead him to find gold in the area. That same streak ran into the water of Back Bay. Off in the distance, what looked like that same streak seemed to reappear on the opposite shore. He put the pieces together, so he thought, and began prospecting on the other side of the lake. This led him and his partner, H. Muir to find what would become Giant Mine, one of Canada's most successful gold mines.

However, that streak of mineralization did not extend to the other side of the lake. It ended in the water. What Johnny found on the other shore was a very rich vein, but completely different geologically from the Burwash claim. In the end, the Giant find was just a streak of good luck!