"He's not slowing down," cried the coach driver. "He's not slowing down!"

Moments later, a semi truck slammed into the side of his coach at full speed, sending it spinning down the highway...

On a cool spring evening in May 2005, a minor traffic accident on the highway between Fort McMurray and Edmonton, Alberta, had blocked up the southbound traffic. Apparently, the driver had gotten tired of waiting and had decided to turn his bus around and look for a different route south.

But the highway was only two lanes wide. As the driver made the turn, the back wheels became stuck in a ditch at the edge of the road and snared the bus. While the driver called for a tow truck, his passengers – tar-sand workers on their way to Edmonton for a week off – got off the bus and stood by the side of the road smoking cigarettes and cursing their luck.

That's when the truck came charging down the highway, unable to see the row of taillights in the traffic jam.

"I looked up to see the semi coming. It just hit us. Everybody went flying everywhere. I couldn't believe what was happening," said one of the workers. "It just T-boned."

The impact pinned many of the onlookers under the bus, killing four workers and injuring dozens more.

The next day, at sunrise, I traveled that same dark highway – in the opposite direction – on my way to the Athabasca Tar Sands...

The Canadian tar sands is a gargantuan oil deposit in Western Canada. They say it holds 1 trillion barrels of oil, although the Canadian Energy Research Institute says only 175 billion barrels are actually recoverable with today's technology. At the current rate of extraction, 175 billion barrels is enough oil to last for another 480 years.

Unlike the conventional oil deposits in the Middle East, where the oil is pumped out as a liquid, in Canada, the oil is trapped in sand. So they dig up the sand using gigantic shovels, move it with some of the largest dump trucks on the planet, and heat it with steam to extract the oil.

It's not as cheap to produce oil from the tar sands as it is to pump it from conventional deposits. But as long as the international price for crude oil is more than $40 a barrel, it's profitable. Besides, Canada is a friendly country. All the other huge oil deposits that the United States relies on lie in distant, unstable countries such as Nigeria, Venezuela, and Saudi Arabia.

Oil companies have been mining the Canadian tar sands since the 1970s. But the boom really started cooking in 2004, when oil jumped above $40 following the invasion of Iraq. Fort McMurray is the town at the center of the oil-sand region. By 2005, the narrow, dark highway between Fort McMurray and Edmonton had become so busy with huge mining trucks carrying equipment and buses carrying tar-sands workers, that while I was there, the press dubbed it:

The most dangerous highway in Canada.

I had gone to the Canadian tar sands that day to see this incredible boom with my own eyes. In 2003, the oil sands business generated $11 billion in revenue. Last year, total revenues exceeded $22 billion. I met 23-year-old high-school dropouts earning $150,000 a year welding pipes together and drifters earning $90,000 a year driving dump trucks.

I checked out accommodation costs. London has the highest rent of any big city in the world. But rent in this small frontier town, deep in the western Canadian wilderness, was even higher. In 2005, you would have paid $1,000 a month to rent a small bedroom in a shared house with three other miners.

Two years later, with oil prices at more than $60 a barrel, business in the Canadian tar sands is absolutely booming. According to Oil and Gas Investor, oil companies are planning to invest more than $125 billion on new oil-sands projects over the next 15 years.

Check out this list of projects coming soon to the tar sands:

Unfortunately, if you're looking to make huge returns in tar sands, I'd say you're about five years late to the party. The boom has been widely reported, and the easy money is long gone. The stocks of Suncor, Shell Canada and the Oil Sands Trust – the big oil-sand producers – are all up hundreds of percent and trade at multiples that already account for the huge growth that lies ahead.

There is a solution. The major oil companies plan to quadruple their production over the next decade or so. They are going to need lots of help in order to pull this off. My strategy: Buy the companies that provide the pipelines, the manpower, the natural gas supplies (for separating the oil from the sand), the heavy equipment, the clean-up services, and the accommodation.