The company that contracted with the school to bring the workers to Williston insisted it decided to stop the program. "We made the decision that J-1 placements were not seasonal or temporary in North Dakota," said United Work and Travel President Kasey Simon.

Nadolny said that the school's contract with Maryland-based United Work and Travel ends this month and will not be renewed.

"Concerns were raised that we were stepping beyond our scope," Nadolny said.

The college housed about 200 workers annually, or about 64 every four months, Nadolny said. The students paid about $100 per week to live in a temporary housing facility on campus and had access to the college's food service and recreational facilities.

Shirvani's letter said the facility where the foreign workers were staying was "not suitable for student housing or long-term occupancy."

Simon said his company has sent hundreds of workers from dozens of countries to North Dakota for the past four years. More than 100,000 foreign college students come to the U.S. each year on under the visa program.

Williston State is the only one of North Dakota's 11 public colleges that has been housing foreign workers, said Linda Donlin, a university system spokeswoman.

Shirvani was traveling to California and could not be reached for comment Wednesday. State Department officials did not return calls.

Nadolny said business and community leaders had pressed Williston State to support the program and provide housing.

The city is in the heart of the state's booming oil patch. Its population has doubled in the past decade to about 30,000 people and the average wage has risen from about $32,000 in 2006 to about $80,000.

Former university chancellor William Goetz, who retired this summer, had approved the contract to house the foreign workers, according to Shirvani's letter.

Melissa Holm, who manages a barbecue restaurant in town, said nearly every service industry business in Williston has used workers from the exchange program. She said the housing shortage makes it difficult to find employees, even though businesses pay at least $15 an hour. One-bedroom apartments in Williston fetch as much as $3,150 monthly, city data show.

She has hired several people in the past two years from as far away as Africa and the Ukraine. Most of the exchange students are extremely hard workers and are needed in town, she said.

"They are irreplaceable," Holm said.

Donlin said housing foreign workers at the school was a liability issue for the university system. The school and its housing, she said, "are intended for students and not intended for people who aren't students."

The housing facility will be razed, Nadolny said. "It's not a safe thing to have empty," he said.