Startup at the Emerald

The impressive beds of sediments on Iron Mountain, near Salmo, B.C., were a challenge to geologists. Beds of argyllite, limestone and quartzite stretched from the Sheep Creek Valley in the west to the Lost Creek Valley in the east. The Emerald ore zone was the result of intrusive granite and diorite that trapped the limestone beds and deposited tungsten minerals. Next to the Emerald ore zone, in the upper limestone beds, was the Jersey lead-zinc deposit. One outcrop was exposed above the Emerald zone, and a second occurred to the east.

Harold Lakes was the Emerald mine’s senior geologist, having helped develop the project during the Second World War. He possessed a broad knowledge of geology and mine exploration in the Kootenays. Moreover, he had an interest in the geology of Iron Mountain.

Harold graduated as a geologist from the Colorado School of Mines and spent his entire life in mine exploration in the western U.S. and British Columbia, including many years in the Sandon and Slocan areas, searching for silver.

When the Second World War erupted, he began exploring for metals needed for the war effort. He returned to the Salmo area, where he had been involved in the mining of the Sheep Creek gold deposit. His new search led him to Iron Mountain, where his samples of a gossan zone indicated the presence of tungsten.

After surveying and sampling the area, Lakes proposed that the Jersey lead-zinc deposit was continuous, stretching over several claims. Surface drilling proved him right. Later, Lakes predicted that folding in the area would yield more tungsten than what was in the Emerald zone. Again, drilling proved him right.

Personally, I found Harold to be a generous, kind and fun-loving person who delighted in sharing his passion for geology. He responded well to young people, and spent endless hours discussing his ideas and interpretations with them. I spent many days with Harold on the slopes of Iron Mountain. Each evening, he pored over the day’s work late into the night. In Harold’s mind, there was an explanation for everything, and he generally found one. There can be no doubt that without the dedication of Harold Lakes, the treasures buried in Iron Mountain would have stayed undiscovered.

When development on the Emerald zone got rolling, other geologists were hired, including Joe Adie, Al Lonergan and Clive Ball. They began an extensive program of surface mapping on the lease claims.

The price of tungsten was volatile. However, the prices of lead and zinc began to escalate during the post-war years, from a few cents per pound to new highs. Wily Harold Lake convinced management at the mine to explore the Jersey zone for lead and zinc, and diamond drilling uncovered a substantial resource. Placer Development decided that both the tungsten and the lead-zinc deposits could be mined simultaneously.

The old mill in the Salmon River Valley was converted to a lead-zinc processing plant. The Jersey zone became home to an impressive underground mine that produced 2,000 tons of ore per day. A second mill built at the Emerald zone processed 1,200 tons per day.

To provide a reliable transport route for the ore, a tunnel was driven from the mine at the Jersey zone through Iron Mountain to the mill at Salmon River.

The Korean War began a few years after the mines opened, and prices for tungsten, lead and zinc rose dramatically. In one year during the war, the mines made a profit of $65 million. Placer Development quickly recovered its capital costs and operated the mine profitably for the next 25 years.

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