When Armand Morin was a junior in high school, hanging out with friends and doing badly in class, his uncle sat him down and told him to do something useful, such as train for a job in the oil industry. So he moved to Fort McMurray, enrolled in a community college program for process engineering and took a job at Shell.

He just turned 23, and last year he made $176,000. After three years, he’ll get a retention bonus. He bought his first home, a three-bedroom, two-story house, for $810,000. He lives with a serious girlfriend. They have a Labradoodle and a pet lizard. They talk about the pluses of having a lawn for children. Upstairs, he has a 70-inch television where they were going to settle in to watch a movie to celebrate his birthday.

“I want to work hard and absorb all this information,” he said, sitting on a brown leather chair in a living room covered with plush white carpeting. He is already moving up the ranks at Shell, where he monitors pressures on pieces of equipment. “But,” he adds, “I’m in it for the money, too. Otherwise I wouldn’t have moved here.”

Morin is just one of thousands of people flocking to Fort McMurray, where the rapid expansion of oil sands mining has turned this northern outpost into a bustling small city. Not all of them have fared well, with many succumbing to drink or drugs; one worker at a bar wrote down on a cocktail napkin, so no one would overhear, that crack cocaine was widespread. Other workers spend their money on travel and inflated rents in a city that is bursting at the seams.

“When I was first elected to the council in 1998, there were 35,000 or 36,000 people living here. Oil was $10 a barrel,” Mayor Melissa Blake said. “We were comfortably built for that environment.”

But then the price of oil started climbing, and the oil sands operations expanded. Today Fort McMurray has more than 100,000 people. Its work-camp population has soared to 35,000, she said.

It’s an odd collection. Among the biggest groups of immigrants: Canadians from the perennially poor province of Newfoundland and Somalis. There is even a person named Shafique Khan running for City Council of this onetime outpost for fur trading with First Nation tribes.

The average age here is 32, and the population is overwhelmingly male. The city has the highest birth rate in Canada.

The rapid growth is putting a huge strain on infrastructure. Blake said it’s hard to keep up. She expects the city to double in size, and she’s trying to extract help from the provincial and federal governments, which collect tax revenue from the oil sands. A key bridge is being more than doubled in size, and the city is finishing a big new water treatment plant. She needs more schools. She’d like to lure a cobbler to Fort McMurray so she could get her shoes fixed. If only things would slow down a bit, she and the city planners might be able to keep up and lower the cost of living and building.

“I loved the recession,” she said. “It was great. We got reasonable pricing.”

Blake said there isn’t enough land to expand city boundaries, because the province owns most of the area and oil companies have leased mineral rights not only up to the edge of town but, in many cases, right under it. One oil venture wants to build steam injection and oil collection facilities next to the airport.

One thing Blake wants to do is turn downtown into a destination. That’s not what it is now, or at least not the kind of destination Blake has in mind. Within a couple of blocks of Blake’s office, there is a gritty bar called the Oil Can, which advertises exotic dancers Monday through Saturday until 2:30 a.m. The Fellowship Baptist Church has homeless people milling about waiting for handouts.

There’s the Boomtown Casino, too, with several of the lights on its sign burnt out. A down-and-out crowd hangs around in front.

David Frances, 53, has a business painting the inside of storage tanks and makes more than $40 an hour. But he said he still lives “paycheck to paycheck.”

Brian MacDonald, 59, a semi-retired electrician, moved here from Nova Scotia 13 years ago. “I kind of got stuck here, I guess,” he said. At first he’d work six months and go home for six months. His wife moved up in 2005, but she didn’t like it. In 2008, she put the dog and cat in the car and moved back home.

On the northern end of town, there is Mac Island, a giant facility financed by Suncor. It has outdoor hockey rinks, a massive indoor water park, a rock climbing wall and indoor basketball and squash courts. One day recently, a golf pro was giving a lesson to a group of children.

People working in the mines can’t afford to be up too late too often. Rush hour begins at 4:30 a.m. and lasts three hours as workers stream to the big pits north of the city. In the fall, Blake set aside a lane of the highway for buses from 5:45 a.m. until 7:45 a.m. to encourage people to leave their cars at home.

“For two hours, I piss off everyone else on the road,” she said. But there’s been a 28 percent jump in bus ridership. “Sustainability makes us cruel masters,” she added.

“I’m in favor of responsible development,” Blake said. “That doesn’t, to me, mean stop growing. It means grow when you’re able to accommodate people.”

Because the city can’t do that, companies are expanding dormitories on their own sites. At Shell’s Albian mines, the company has put up a dormitory that houses 2,500 people. Each person has his or her own room with a television and access to a gym and lounge, where people drink or watch movies. Some companies, however, ban drinking in the camps.

People usually work 10 hours a day, four days a week, though some do two-week spells in order to take longer breaks.

Thursdays are big shift-change days, and the airport one recent Thursday was packed with people trying to get out. Many travel to the United States for vacation. Others are arriving.

The big incentive is the money. A cab driver from Bulgaria compared it to volunteering for prison, saying he had been “serving time” in Fort Mac, as it’s often called, for seven years. He said Fort McMurray was good for one thing: “Work.”

One of the newest arrivals in Fort McMurray: Armand Morin’s father. A mechanic from Calgary, he could double his income. He is working for Canadian Natural Resources, living in a camp and getting free flights back home every few months. But he isn’t making as much as Armand, an unusually focused young man.

Some people come to Fort McMurray to save money, then spend it all on entertainment, travel, booze or drugs, he said.

“If you work overtime, you can make $180,000 a year and have nothing to show for it,” Morin said. “The amount of money people have here will destroy you if you don’t have discipline.”