The number of rigs actively exploring for or producing oil and gas in North Dakota hit a new low Monday at 80, state data show.

The number of rigs in service in North Dakota, a state at the heart of the shale oil and gas boom, was down 62 percent from 2012 levels and 57 percent lower than this date in 2014.

State data show oil production in March, the last full month for which data are available, was 1.19 million barrels per day, a 1 percent increase from the previous month, but 2.6 percent below the all-time high reached in December 2014.

The state's oil and gas division reported the number of wells in production in March, however, were at an all-time high at 12,439.

Lower oil prices, down about 40 percent year-on-year, are leaving energy companies with less to spend on oil and gas exploration and production.

Oil field services company Baker Hughes said Friday there were eight fewer rigs actively exploring for or producing oil and gas in North America and 49 fewer internationally than for the week ending May 15. The pace at which drilling activity in North America is declining is slower than when oil prices hovered near $50 in early 2015.

An early May presentation from North Dakota show a forecast of 140 rigs in active service with oil priced at around $60 per barrel, relative to the current level. Oil production at that price range is expected to hold 1.2 million barrels per day through 2016, but drop off somewhat to 1.15 million the following year. Oil production increases through 2017 only if markets breach the $90 per barrel threshold.