Abandoned St Catharines GM Plant plant in St Catharines, Ontario Canada.
Once a major employer in this large Ontario city the abandoned St Catharines GM Plant now sat silent and in limbo as developers decide what to do with the buildings and all of its industrial contents. The St Catharines GM Plant has since been demolished
For more than a century, the massive industrial complex on Ontario Street in St. Catharines was a major part of the city’s identity. Today, the former General Motors property sits largely abandoned, its empty buildings and deteriorating industrial infrastructure marking the end of an era of Canadian manufacturing.
The property at 282 and 285 Ontario Street covers roughly 20 hectares, or 50 acres, and has a history stretching back to the early 1900s. Before it became General Motors property, it was home to McKinnon Industries, one of St. Catharines’ most important manufacturers. McKinnon began on Ontario Street in 1901 and eventually became a major producer of automotive components. General Motors purchased the company in 1929, bringing the site into the GM family.
Over the following decades, the plant expanded dramatically. It produced everything from axles, gears and transmissions to engine components and other automotive parts. During the Second World War, the factory also shifted toward military production and employed approximately 4,200 people.
By the middle of the 20th century, General Motors was one of the most important employers in St. Catharines. The sprawling complex contained foundries, machine shops, production areas, warehouses, offices and countless pieces of industrial equipment.
But the automotive industry was changing.
Manufacturing became increasingly global, production was consolidated and older facilities became less competitive. The St. Catharines operation gradually declined, with portions of the complex closing over the years.
In 2010, General Motors finally ended manufacturing at the Ontario Street property.
The closure marked the end of more than 100 years of manufacturing on the site and left behind one of the largest industrial properties in the city. GM eventually sold the property in 2014.
The Demolition That Stopped
The plan was not to leave the factory abandoned forever.
A major redevelopment was proposed, with the former industrial property envisioned as a new mixed-use community containing residential and commercial development.
Demolition began in 2016.
But the transformation never happened as planned.
Much of the complex was demolished, leaving large areas of vacant land, foundations and industrial debris. Other major sections of the factory remained standing. Eventually, demolition and redevelopment stalled, leaving the property in a strange halfway state.
For years, the site remained largely untouched.
And that is what made it so fascinating.
Exploring the GM Plant
RiddimRyder Photography and I were up early to meet and head for the General Motors (GM) Ontario Street components plant in St. Catharines.
The plant had closed in 2010 and was later sold to BayShore Groups in 2014.
In the summer of 2015, the site was good and ready for us, still filled with machines and equipment and tools, and the site still had power.
We only had to worry about one lone security guard who was sitting and listening to music in his office, we pretty much walked right by his office at one point and he had no idea!
Our exploration started on the north side of the property by entering from the ravine between the plant and 12 mile creek.
We would navigate the mammoth plant, it’s towering machines, corridors and various buildings until we had documented everything possible.
Now was the tricky part!
The north and south buildings are connected by a tunnel that goes beneath Ontario street, and the security guards office was just to the left of the stairs coming up from the tunnel.
The door to the south plant from the tunnel was a large metal door with a crash bar, so we had to push and open with deathly silence and surgical control.
Then, once through the door, we had to go up a small set of stairs to get to the shop floor. We had to watch every step to make sure we weren’t going to step on anything or kick anything.
At the top of the stairs, we heard music coming from the security office and his gold cart was parked outside the door.
We tip toed from the stairs, making a hard right and stealthily hauled ass all the way as far as we could get from the office,
We made our way all the way to the southernmost wall and then zig zagged our way through this side, which was much larger than the north side.
After several hours spent inside, we had seen all that we wanted to see and we made it out and to freedom without being seen!
Now, the plant has been largely demolished, but not entirely and there is an ongoing battle between the city and the BayShore Group about keeping the site contained, locked and safe.
Environmental Problems
The future of the property has been complicated by its industrial history.
After decades of heavy manufacturing, the former GM lands became a significant brownfield redevelopment project. Environmental investigations have identified contamination issues, including concerns surrounding industrial pollutants and contaminated stormwater.
The site sits beside Twelve Mile Creek, making environmental management particularly important.
The City of St. Catharines has been involved in efforts to address environmental, safety and trespassing concerns for years. In 2020, the city created a specific action plan for the property following concerns about the condition of the site and potential environmental hazards.
The environmental work has been one of the major obstacles to redevelopment.
Cleaning up a 50-acre former industrial complex is an enormous undertaking, particularly when demolition, contaminated soil, buried foundations and other industrial remnants are involved.
What Happens to the Property Now?
The city has already changed the property’s planning designation.
In 2021, the former GM lands were officially redesignated from Employment to Mixed Use, opening the door to future residential and commercial development.
The City is now working on the Ontario Street Corridor Secondary Plan, which includes the former GM property as one of its primary areas of focus.
The long-term vision is for the area to eventually become a large mixed-use neighbourhood, potentially incorporating housing, retail, commercial space, parks, trails and improved connections throughout the Ontario Street corridor.
The planning process was paused in 2024 but was restarted in late 2025, with the City now working toward bringing a proposed Secondary Plan to Council in 2026.
At the same time, the condition of the remaining buildings has become an increasingly serious issue.
In May 2026, following complaints and an inspection of the property, the City ordered the owners to repair, replace or demolish buildings that were considered unsafe. The order reflects just how far the remaining structures have deteriorated.
The City is also considering financial incentives specifically designed to help with the enormous cost of remediating and redeveloping the former GM lands.
The End of an Industrial Era
The future of the former GM plant is almost certainly not going to involve preserving the old factory.
Eventually, the remaining buildings will likely be demolished and the land remediated for a completely different purpose.
What eventually replaces it could be a new neighbourhood containing thousands of residents, businesses, parks and public spaces.
But beneath that future development will be the history of McKinnon Industries and General Motors.
For more than a century, people came to this property to build the components that helped put North Americans on the road. Generations of St. Catharines families were connected to the factory, and its importance to the city’s economy cannot be overstated.
When I explored the site in the summer of 2025, I was walking through a place that was already disappearing.
The factory had been closed for 15 years. Parts of it had already been demolished. Other sections were deteriorating rapidly.
But there was still an incredible amount left behind.
Machinery, buildings, signs, equipment and countless small details remained as reminders of what this place once was.
Today, the former GM lands are entering another chapter.
The abandoned factory will eventually disappear completely.
The photographs taken during its final years, however, will preserve what was left behind.