The cost of a new oil refinery near Dickinson is rising due to delays in getting the facility up to full production.
The Dakota Prairie Refinery started accepting crude late last year, but bitter cold weather and electrical system revisions have pushed back full production until at least April.
Officials say the plant is now expected to cost more than $400 million, about $50 million more than the previous estimate.
Bismarck-based MDU Resources Group and Indianapolis-based Calumet Specialty Products Partners broke ground on the refinery in March 2013. Once it is fully operational, it will process 20,000 barrels of oil each day into 7,000 barrels of diesel fuel and other products.