Canada’s tar sands, officially called oil sands, are located in northern Alberta. They cover approximately 142,200 square kilometers of land, an area roughly the size of England, spread across three major deposits: Athabasca, Cold Lake, and Peace River.
The Three Oil Sands Deposits
The Athabasca deposit is by far the largest and most well-known. It sits in northeastern Alberta, centered around Fort McMurray, and is the only deposit where the bitumen (a thick, heavy form of petroleum) sits close enough to the surface to be extracted through open-pit mining. Reserves within 75 metres of the surface qualify as mineable, and that mineable zone covers about 4,800 square kilometers, or roughly 3.4% of the total oil sands area.
The Cold Lake deposit lies to the southeast of Athabasca, near the city of Cold Lake along the Alberta-Saskatchewan border. The Peace River deposit is the smallest of the three and sits in northwestern Alberta, closer to the town of Peace River. In both of these deposits, the bitumen is too deep underground for surface mining, so it has to be extracted using drilling techniques that pump steam underground to heat and loosen the bitumen so it can flow to the surface.
How the Oil Is Extracted
Only a small fraction of the oil sands are mined in the way most people picture: massive open-pit operations with enormous trucks hauling loads of dark, sandy earth. That kind of mining only happens in the Athabasca region where deposits sit near the surface. In 2024, surface mining accounted for 48% of total raw bitumen production, producing about 1.72 million barrels per day.
The remaining 52% of production comes from in-situ methods, where wells are drilled deep into the ground. The most common technique involves injecting high-pressure steam to soften the bitumen so it can be pumped up through a second well. This approach leaves the surface largely intact compared to open-pit mining, but it requires significant amounts of energy and water to generate that steam.
The Scale of the Operations
To put the size of these deposits in perspective, 142,200 square kilometers is larger than many countries. The deposits contain one of the largest proven oil reserves in the world, trailing only Venezuela and Saudi Arabia in total volume. Not all of that land is actively being developed. The surface-mineable portion, at 4,800 square kilometers, is still a substantial area, but it represents a small slice of the total footprint.
The operations have created a visible industrial landscape in northeastern Alberta. Tailings ponds, which hold the wastewater and residual material left after bitumen is separated from sand, cover roughly 220 square kilometers and contain over a billion cubic meters of tailings. These ponds are concentrated in the Athabasca region near the mining operations and are one of the most contentious environmental features of the industry.
Why They’re Called “Tar Sands”
The term “tar sands” and “oil sands” refer to the same thing: naturally occurring deposits of sand, clay, water, and bitumen. The industry and the Alberta government prefer “oil sands” because the substance is technically bitumen, not tar. Environmental groups and critics tend to use “tar sands” to emphasize the heavy, polluting nature of the resource. Both terms appear widely in news coverage and public conversation.
The bitumen itself is so thick at room temperature that it won’t flow on its own. It has to be either mined and then mixed with hot water to separate it from the sand, or heated underground until it becomes liquid enough to pump. Once extracted, it needs further processing or dilution before it can travel through pipelines to refineries, most of which are located in the United States or elsewhere in Canada.