Cochrane Hill
Like so many of Nova Scotia’s historical gold districts, Cochrane Hill has the potential to be mined again, to create jobs for Nova Scotians and provide an essential material we all use every day (it’s in the device you’re reading this on!).
In fact, almost all the activity in Nova Scotia’s gold sector is at historical mines where deposits were proven during our early gold rushes, but modern science and technology make it possible to mine again while, of course, taking proper care of the environment.
Gold mining started in Cochrane Hill in 1868 when a shaft was sunk by a Mr. Cumminger, who was also very active in the nearby Goldenville gold district.
In 1869, a number of veins were opened by three different operators: the Cochrane Hill Company, Kirk and Company and a Mr. McDonald. A 15-stamp mill was also built to process ore at Melrose, about 2.5 miles to the northwest. The stamp mill was run by waterpower.
(Most Nova Scotia gold is in quartz veins, which means the gold needs to be separated from the quartz and other host rock. The first step is to pulverize the rock/ore so the gold can be chemically separated from it. The most common technology in Nova Scotia for pulverizing ore in the second half of the 1800s and early decades of the 1900s was the stamp mill – a large machine that crushed gold-bearing rock by stamping it over and over.)
Little work was done in the years following 1869 other than some prospecting.
In 1877, 188 tons of ore were milled, producing 48 ounces of gold. For the next few years, Cumminger and several others did intermittent work.
In the 1890s and early 1900s, several operators worked in the area on and off. In 1907, 560 tons of quartz were crushed, producing 113 ounces. However, operations shut down again that year and the mine was allowed to fill with water.
In the 1920s, the California Gold Mining Company worked in Cochrane Hill and in 1927, the Novamac Mines and Power Corporation built a 10-stamp mill, deepened the shaft on the Mitchell belt by 100 feet (making it a total depth of 220 feet at that time) and did additional tunnelling. This work produced 152 ounces of gold, but the company then ceased operating in Cochrane Hill and instead concentrated in Goldenville.
In 1934, Cochrane Hill was taken over by the Eastern Mining Syndicate Ltd. A company memo written in September 1935 said, “the mine has telephone service,” which was something worth highlighting in that era. (Phone service cost the company $255.49 in 1934.) The memo also said Sherbrooke, nine miles away, “is in weekly communication with Halifax by boat.” These comments are reminders that Nova Scotia’s historical gold miners worked in a much simpler time, with only rudimentary science and technology compared to the sophisticated, science-based activity that modern mining is.
The Eastern Mining Syndicate built ten new buildings in 1934 and invested in many improvements, including installing a new power plant and water system, and significant mine development work, in anticipation of restarting the mine. (See the hand-drawn mine surface plan below.) However, despite spending $66,854.47 that year, the company still needed financing to put the mine into production and the financing never materialized.
After the Eastern Mining Syndicate era ended in 1936, the Cochrane Hill property was held by various companies and individuals, but little work was done. From the 1960s to present, it has been an exploration target, including in the 1980s when Northumberland Mines Ltd. extracted a bulk sample, built a mill, did significant exploration and drove a decline tunnel to connect with the Mitchell shaft. However, Northumberland ceased work without putting the mine back into full production.
The Cochrane Hill Gold District also included Crow’s Nest, which is two miles west of Cochrane Hill. Mining started there in 1878 but little was done until 1885-86 when a Mr. Fraser started doing development work that continued on and off for a decade. W. H. Weston then did additional work for another five years.
At Crow’s Nest, the hill is 200 feet tall and the mining was done by means of adits (tunnels) dug into the side of the hill.
Miners working the Stake and Belt veins in Crow’s Nest ran into a fault, bringing work on them to an end. In geology, a fault is a fracture, or zone of fractures, between two blocks of rock that allows the blocks to move relative to each other. Faults are caused by geological forces like tectonic plate movement. They are a challenge in mining because they can cause deposits to be split, moving part of the deposit to a different, often hard-to-find, location. In the case of Crow’s Nest, the fault split the gold-bearing quartz veins and the rest of the veins could not be found.
Despite the area’s obvious potential, the recorded production from the Cochrane Hill district from 1877-1982 was only 2,081 ounces of gold.
Mining in the Cochrane Hill district was done both underground by shafts and tunnels and by “open pit” - what we call a surface mine today. The vast majority of historical gold mining in Nova Scotia was done by digging shafts and tunnels to follow quartz veins that contained gold. As long as the veins contained enough gold, this could be a very profitable method, but it was difficult and expensive work to dig underground.
Surface mines, both historically and today, let companies access lower-grade ore but much more of it, making it a viable method, especially in the modern era as the science of metallurgy – separating minerals from their ores – has become so sophisticated. Today, most mines in Nova Scotia are surface mines, including the Moose River gold mine which opened in 2017.
