A power outage in North Dakota's capital on Wednesday brought down computer servers that provide data used to track myriad output statistics across the second-largest U.S. oil producing state, Reuters said July 8.

The outage means the state's daily drilling rig count - a closely watched number that can offer guidance on future oil production - is not available. The count stood at 76 on Tuesday, near where it has been for several weeks.

The rig count is tabulated daily by the state's Department of Mineral Resources (DMR), North Dakota's oil regulator. Field inspectors upload data to servers in Bismarck, which aggregates the data and automatically publishes it to a public website every day.

The DMR website also provides in-depth data on the depth and length of the state's nearly 15,000 wells, as well as oil production history. A mapping function graphically shows much of this data, including the location of each drilling rig operating in the state.

"We're hoping to get power back soon to the servers, but we're just not sure on timing," said Alison Ritter, a DMR spokeswoman.

MDU Resources Group, which owns the utility for the region, reported that a problem at a substation in northern Bismarck cut electricity to an unknown number of customers. Crews arrived on the scene at roughly 8:30 a.m. local time (1330 GMT) to assess damage, said Rick Matteson, an MDU spokesman.

"They're not sure what the problem is and they don't as yet have an estimate for a restoration time," Matteson said.

Utility customers reported waits of more than 90 minutes to contact MDU's customer service line.

North Dakota produces roughly 1.2 million barrels of oil per day, according to the latest monthly report from the DMR.

Production statistics for May are scheduled to be released on Friday.