All but 55 customers of Montana-Dakota Utilities in Tioga had their natural gas service restored by 3 p.m. Wednesday after a citywide outage the day before.

MDU spokesman Mark Hanson said the outage affected 909 customers in Tioga, stemming from an apparent failure in the gas supplier's backup system during maintenance Tuesday afternoon. 

Fifty MDU technicians from around North Dakota and eastern Montana traveled to Tioga Tuesday evening to manually reset every customer's natural gas meter and relight appliances.

Techs worked throughout the night to correct services for 650 customers by 8 a.m., Hanson said. MDU prioritized Tioga's nursing home and hospital, Tioga Police Officer Mia Lefever said Tuesday.

Tioga's coal-heated high school opened as a shelter for those residents without heat. Principal Brodie Odegaard said, as far as he knew, no one stayed at the school.

Tioga Police Chief Corey Murphy said police had no calls for service related to the outage during the night and Wednesday morning.

"I think everybody's been warm," he said around noon Wednesday.

MDU's local district representative will now work with the city to contact any residents or businesses who have not responded to technicians' visits.

"We'll be working a number of different ways to get those final ones," said Hanson, adding they might be using auto dialer phone messages and a website alert. 

He said he knew of no frozen pipes or related problems from the outage.

Temperatures dropped to single digits in Tioga overnight into Wednesday, with a high of 8 during the day.

Tioga is a city of about 1,600 residents in northwestern North Dakota, about 40 miles east of Williston. 

Reach Jack Dura at 701-250-8225 or