Nathaniel Kroshus didn't come here for high wages or to escape his past. He's here chasing his passion.

The 31-year-old from Grand Rapids, Minn., loves to teach music. But a dearth of music-teaching jobs in budget-wracked schools back home sent him nearly 600 miles west in 2012 with his fiancée, Trisha, their cat, Gulliver, and Juno, a gray-eyed white Husky.

"I knew the experience would be like hell," said Nate, a whitecap in this historic wave of migration making North Dakota the fastest-growing state. "But I didn't really realize how hellish till I got here."

He was sitting on a couch last spring, eating Noodle Roni with mock chicken and a salad that Trisha, a vegetarian from Medford, Minn., just prepared. They were paying $1,800 a month for one-third of a trailer at the Hexco man camp, 400 square feet of space down a snaking dirt road north of Williston.

The place had no address. The sink and shower leaked. The microwave outlet didn't work "and the walls are so thin, we cannot only hear the kid next door, we can follow what TV shows he's watching," Trisha said.

"I knew it would be expensive, but didn't believe it would be this expensive," she said. "I thought there would be older ladies with rooms to rent. There are not. This place is a cave and the space is so crowded, we want to kill each other."

Nathaniel Kroshus and fiancée Trisha first stayed in a 400-square-foot trailer compartment (above) near Williston and paid $1,800 a month. Their new apartment is nearly twice as roomy and rents for a third less.

Instead, they returned to Trisha's home near Owatonna on summer break and got married in Hastings.

Trisha kept her "fingers crossed that a call would come with a job in Minnesota," but when that didn't happen, she shrugged.

They headed back to the Bakken, where hotels and apartment buildings had sprung up in and around Williston nearly as fast as oil rigs — a building boom within an oil boom.

Their new apartment building opened in August near Williston's almost-done, $70 million recreation center. Their top-floor apartment is 728 square feet — nearly twice as roomy as their man-camp cave, It rents for a third less, $1,250, including the $100 fee for Gulliver and Juno.

Nate's salary, meanwhile, has jumped nearly 20 percent to $50,400.

"The perception is everyone's rich out here, but I'm still making about half the median ­salary of $88,000," he said. "But it's an opportunity for me, and I am excited to share the lifelong gift of music."

Trisha has landed a support job at a school here.

"It's better," she said. "But it's still Williston."