Ahead of a special legislative session to review the state budget, North Dakota state data show a modest recovery underway in oil and gas exploration activity.

State data show 35 rigs actively exploring for or producing oil and gas as of Monday, an increase of nearly 10 percent from last week. The move in North Dakota mirrors developments elsewhere in the United States, where relative stability in crude oil prices, since a collapse below $30 in early 2016, is building confidence in the industry.

For the fifth week in a row, oilfield services company Baker Hughes reported an increase in exploration and production activity in the United States. Gauged by rig counts across the country, activity increased about 1.5 percent for the week ending July 15.

Nevertheless, the North Dakota rig count is still down more than 50 percent from this date in 2015. Faced with a potential budget crunch, the state's governor called for a special legislative session Tuesday to review the situation.

In a mid-July executive order, North Dakota Gov. Jack Dalrymple called for the special session "to make needed adjustments to the state budget due to lower than forecasted tax revenue totals."

Without a course correction, the state estimates its general fund will be short about $310 million by the end of the current biennium.

State data show crude oil production in May, the last full month for which data are available, was 0.5 percent higher than the previous month to average 1.04 million barrels per day. The all-time high was 1.23 million bpd in December 2014.

May rig counts in North Dakota were at or near record lows. The all-time low point for rigs in North Dakota is zero.