BISMARCK, N.D. (AP) — State officials say a pair of blizzards that smacked North Dakota in April caused a dramatic reduction in oil production.

The Bismarck Tribune reported that State Mineral Resources Director Lynn Helms provided state regulators with updated production estimates Friday.

He said the state’s oil industry had been producing about 1.1 million barrels daily until the blizzards hit. The first storm began on April 12 and lasted three days.

Helms says it caused production to fall to about 750,000 barrels per day.

The industry had rebounded to 950,000 barrels per day when the second storm hit on April 23. That blizzard caused production to drop to just 300,000 barrels per day.

Production has since increased to about 700,000 barrels per day.