North Dakota's oil production in May climbed to nearly 1.25 million barrels per day, hitting another record for the nation's second-largest producer of oil.

The North Dakota Department of Mineral Resources on Friday reported the data, which was up about 5 percent, or 19,000 barrels a day, from April.

About 96 percent of the total 38.6 million barrels of oil pumped in May came from the state's lucrative Bakken formation and Three Forks oil fields, state officials said.

North Dakota saw its natural-gas production jump 6.8 percent to a record 71.9 million barrels in May.

Lynn Helms, director of the state's mineral department, said in a statement that the number of oil rigs operating within the state increased from 60 to 62 during the month of May. Another five rigs have been added since May for a total of 67, he said.

"Operators have shifted from running the minimum number of rigs to incremental increases and decreases as the [West Texas Intermediate price benchmark] moves between $45 and $60 a barrel," he said.

The WTI has remained above $55 per barrel for more than 90 days, so the rig count is expected to continue increasing, he said.

The price for North Dakota sweet crude hit $55 in April, $58 in May, $55 in June and is now trading near $62 a barrel.

Industry observers noted that U.S. oil output has been pretty robust so far this year. Global economic growth has proved strong, underpinning oil demand. At the same time, oil prices have been rising, which has increased potential profits for oil producers.

Dee DePass • 612-673-7725