SIDNEY, Mont. — For most high school seniors, a college degree is the surest path to a decent job and a stable future. But here in oil country, some teenagers are choosing the oil fields over universities, forgoing higher education for jobs with salaries that can start at $50,000 a year.

It is a lucrative but risky decision for any 18-year-old to make, one that could foreclose on his future if the frenzied pace of oil and gas drilling from here to North Dakota to Texas falters and work dries up. But with unemployment at more than 12 percent nationwide for young adults and college tuition soaring, students here on the snow-glazed plains of eastern Montana said they were ready to take their chances.

“I just figured, the oil field is here and I’d make the money while I could,” said Tegan Sivertson, 19, who monitors pipelines for a gas company, sometimes working 15-hour days. “I didn’t want to waste the money and go to school when I could make just as much.”

Less than a year after proms and homecoming games, teenagers like Mr. Sivertson now wake at 4 a.m. to make the three-hour trek to remote oil rigs. They fish busted machinery out of two-mile-deep hydraulic fracturing wells and repair safety devices that keep the wells from rupturing, often working alongside men old enough to be their fathers. Some live at home; others drive back on weekends to eat their mothers’ food, do loads of laundry and go to high school basketball games, still straddling the blurred border between childhood and adulthood.