WILLISTON, North Dakota - Christina Knapp and a friend were drinking at a bar in a nearby town recently when about five men called them over and made an offer.

They would pay the women $3,000 to strip naked and serve them beer at their house while they watched mixed martial arts fights on television. Ms. Knapp, 22, declined, but the men kept raising the offer, reaching $7,000.

"I said I make more money doing my job than degrading myself to do that," said Ms. Knapp, a tattoo artist.

The rich shale oil formation deep below the rolling pastures here has attracted droves of young men to work the labor-intensive jobs that get the wells flowing and often generate six-figure salaries. What the oil boom has not brought, however, are enough single women.

At work, at housing camps and in bars and restaurants, men have been left to mingle with their own. High heels and skirts are rare around here. Some men liken the environment to the military or prison.

"It's bad, dude," said Jon Kenworthy, 22, who moved to Williston from Indiana in early December.

This has complicated life for women in the region as well.

Many said they felt unsafe. Several said they could not even shop at the local Walmart without men following them through the store. Girls' night out usually becomes an exercise in fending off obnoxious suitors.

"So many people look at you like you're a piece of meat," said Megan Dye, 28, a nearly lifelong Williston resident. "It's disgusting. It's gross."

Prosecutors and the police note an increase in crimes against women, including domestic and sexual assaults. "There are people arriving in North Dakota every day from other places around the country who do not respect the people or laws of North Dakota," said Ariston E. Johnson, a deputy state's attorney.

Over the past six years, North Dakota has become the state with the third-highest ratio of single young men to single young women in the country. In 2011, nearly 58 percent of North Dakota's unmarried 18-to-34-year-olds were men, according to census data.

Some women have taken advantage of the female shortage. Williston's two strip clubs attract dancers from around the country. Prostitutes from out of state troll the bars.

Natasha, 31, an escort and stripper from Las Vegas, is on her second stint here. Business in her industry is much better here than in the rest of the country, she said. She makes at least $500 a night, but more often she exceeds $1,000. "We make a lot of money because there's a lot of lonely guys," she said.

On a recent night at City Bar in nearby Watford City, the only women in the room were two bartenders and the woman running the karaoke. Under flashing lights, some of the male patrons huddled at the bar, while others played games like darts.

"Out here, you can't tell a guy, like, 'I had a rough day,'" said Zach Mannon, 23, who has been working in the oil patch for three years. "They're going to go, 'Everyone has a rough day. Get over it, you sissy.'"

Some men have forced themselves on women. And some women have begun taking aggressive steps to protect themselves.

Jessica Brightbill, 24, said she was walking to work in the afternoon when a car with two men inside pulled up behind her. One got out and grabbed her. A man in a truck pulled up and began yelling and she got away, she said. The episode left her rattled. Going out alone is now out of the question.

Barbara Coughlin, 31, is getting a permit to carry an electroshock weapon. Her family hardly ever lets her go out on her own - not even for walks at the housing camp where they live.

"Will I stay for very long? Probably not," she said. "To me, there's no money in the world worth not even being able to take a walk."

The New York Times

(China Daily 02/03/2013 page10)