The Bakken reserve area is associated with the Williston Basin, which includes the Three Forks Formation. The U.S. Geological Survey estimates the area contains as much as 7.4 billion barrels of oil and 6.7 trillion cubic feet of natural gas.
The North Dakota Department of Mineral Resources published production figures for April, the last complete month for which information is available.
The state government said oil production reached an all-time high of 793,249 barrels per day in April, a 1.3 percent increase from March. For natural gas, production increased 3 percent from March to a record of 860 million cubic feet per day.
Lynn Helms, North Dakota's resource director, said 95 percent of the drilling activity in the state targets the Bakken and Three Forks formations.
Helms said oil and natural production increased despite inclement weather. April snowfall was the highest on record for the month, he said. Most of the state's highways were closed in April because of heavy snowfall. Helms said May rainfall was heavy as well.
"Operators have not been able to catch a break," he said in a statement published Monday.