Silver Islet from above

The surprising, shocking, startling, astonishing story of Silver Islet

Today’s post comes from Will Oades, Natural Heritage Educator at Sleeping Giant Provincial Park. Header photo: Jeff Robinson.

Have you ever applied for a job, shown up on the first day of work, and realized it was nothing like you thought it would be? That was the case among many of the men coming to work at the Silver Islet Mine.

Known as the world’s richest silver mine, Silver Islet’s mine shaft was beneath the icy waters of Lake Superior; a small yet significant piece of information that was missed by some of the miners before arriving. Though the majority of the miners stayed to do the job that they were hired for, some of them decided that travelling into the belly of the earth, underneath billions of litres of water was just a little too dangerous for their liking.

The task at hand

Anyone who lives on the shore of Lake Superior, or has lived in the proximity of the lake, knows it is incredibly unpredictable and extremely dangerous. The lake can be completely calm, then transform minutes later into a raging sea that makes even the most seasoned of sailors queasy.

Lake Superior Coastal Trail, north of Sinclair Cove

These conditions made creating a 365 m deep hole in the ground, underneath the lake, an incredibly difficult task. Additionally, for the mine to be operational, they would have to protect the small island itself, and have pumps always running to clear out the water constantly collecting in the bottom of the mine shaft.

Tackling Lake Superior

This task was deemed not worthwhile by the Montreal Mining Company, who originally owned the mine, and later sold it in 1870 to Alexander H. Sibley, the president of the Silver Islet Mining Company. Little did the Montreal company know, they had just lost their chance of operating one of the world’s most successful silver mines.

The President’s mansion: summer headquarters for shareholders and families

When considering the best plan of attack for protecting the mine from the fierce storms of Lake Superior, it was important to consider all options. One engineer suggested building a wall 9 m high around the 2,468 m2 island. This would have cost a hefty two million dollars in 1870, which would be worth almost thirty-seven million dollars today.

Someone else suggested building a system of smaller walls and pumps that would have cost only one million dollars. However, both of these options were incredibly expensive and neither could guarantee that the islet would remain safe.

A preposterous plan

Deciding on a plan to protect the islet was overwhelming for the Silver Islet Mining Company and it wasn’t until William. B. Frue became lead engineer that they had a clear direction. Frue’s plan was to build a breakwall to protect the islet, and use a pump to keep water out of the mine shaft.

Black and white photo of small island with a variety of mining operation buildings
Mine buildings on Silver Islet

This plan would only cost approximately fifty thousand dollars and required only 34 workers to set up and get the mine operational. To anyone in the mining industry, hearing that a mining company was trying to dig into the ground under a lake to harvest silver on a fifty-thousand-dollar budget with only 34 men sounded preposterous!

Not for the weak-willed

Black and white photo of shoreline with buildings along
Buildings on Silver Islet

Now imagine the Canadian track and field team running four 100 m relays around a 400 m track. Picture that distance going straight down into the depths of Lake Superior. That’s approximately the depth of the mine shaft (384 m deep) and about how deep the miners had to travel into the ground every day.

Even today, a mine of this size is considered quite substantial and requires a lot of planning and advanced technology to ensure the safety of the miners. The mine shaft got so deep that eventually the timber supports being used were unable to support the weight of the overhanging mass of rock.

Brown model of mining operations
Model of Silver Islet Mine on display at the Sleeping Giant Visitor Centre

Instead of loading the mine shafts with timber supports, Frue left a thick vein of silver running all the way down the mine shaft to take the load from the roof. This was a smart move because eventually they would be able to collect this vein of silver. Instead of paying more for supports, the supports ended up paying them!

Crucial communications

Communication was another added obstacle for the mining community at Silver Islet. Today, if a message to a friend or family member needs to be sent, it’s a matter of seconds and requires little thought or effort. For the miners and their families at that time, mail was the only method of communication and therefore the only way to let far-off family members know they were still alive.

Since there were no roads that led to the community onshore, the only way mail could reach them was by boat or dogsled (when the lake was frozen). As a result, delivery of mail was inconsistent and inconvenient. Especially for Frue, who needed to stay in touch with Alexander H. Sibley to successfully operate the mine.

Black and white image of dark two story structure with flag flying out front
Mining office with Union Jack flag flying

The Silver Islet Mining Company was based out of the United States. Mail crossing the border had to first travel to the Pigeon-River Border Crossing before eventually crossing into America. When labour issues caused the U.S. mail contractors to refuse to carry any mail destined for Canada, this led to a critical lack of communication between Frue and Sibley.

Luckily, a deal was made and the transportation of mail became regulated, at great expense to the mining company. Once mail did arrive, people knew it had come when the postmaster raised the Union Jack flag. Whereas today, people have instant notifications on their phones letting them know of an email that was probably only sent moments before.

The demise of the Silver Islet Mine

Eventually, the mine’s remote location brought operations to an end after thirteen years of extracting silver from underneath Lake Superior’s icy waters. A crucial shipment of coal was not delivered to Silver Islet in time to keep the water pumps running and because of this, the mine was reclaimed by Lake Superior.

Black and white image of half sunken island community
Old Silver Islet Mine taken in 1890, some years after closing

Although the mine has been closed now for over 100 years, the on-shore community at Silver Islet remains with some of the original miner’s homes still standing. Some of these historic buildings have been renovated and the shore is now lined with summer camps in the shadow of the sleeping giant that lays, protecting the sunken mine shaft.

A historic destination

Today, the mine and the area of Silver Islet continue to intrigue visitors enjoying the recreational opportunities at Sleeping Giant Provincial Park. And in fact, without Silver Islet mining operations, no roads would have been built out onto the Sibley Peninsula when they were and Sleeping Giant Provincial Park may not be the same today.

Blue three story building on a shore
Silver Islet general store

The recreational trails and campsites scattered across the park are now filled with laughter, smiles and good times, perhaps reminiscent of the comradery and bonds made between miners in the days of the mine.

Model of mine cross section
Part of the Silver Islet Mine display at Sleeping Giant

If you are interested in reading more about the Silver Islet mine, Silver Under the Sea: The Story of the Silver Islet Mine Near Thunder Bay, Ontario, Canada by Helen Moore Strickland and Silver Islet: Striking it Rich in Lake Superior by Elinor Barr are both very thorough and informative books that provide a unique perspective on all aspects of the mining community.

Next time you’re visiting Sleeping Giant Provincial Park, be sure to stop in at the park’s Visitor Centre to learn more about the history of the Silver Islet Mine (including models of the mine, and a mine shaft that you can even walk through to get the feel for a miner’s daily life).