Josh Wood, File, Associated Press
In this Sept. 16, 2014 file photo, Mark Fox, a candidate for chairman of the Mandan, Hidatsa and Arikara Nation, poses for a photo in New Town, N.D. Fox, one of two remaining candidates running to be the next leader of an oil-rich North Dakota American Indian nation, says he will work to slow oil development if environmental protections there cannot be met.

WILLISTON, N.D. — One of two remaining candidates for leader of North Dakota's oil-rich Mandan, Hidatsa and Arikara Nation said he would work to slow the pace of oil development if environmental protections are not guaranteed.

"I'm not a great advocate of the oil industry and rapid development," candidate and tribal tax director Mark Fox said earlier this week after primary election results showed he would remain in the race for tribal chairman. "I will slow it down if we cannot get the protections that we need so that we can have the same reservation that I grew up in and the elders grew up in."

Fox faces tribal attorney Damon Williams in the Nov. 4 election. Current chairman Tex Hall, whose administration has presided over the bulk of the tribes' oil development in the past four years, did not receive enough votes to advance in the race.

The tribes' Fort Berthold Indian Reservation currently produces in excess of 330,000 barrels of oil a day, roughly a third of North Dakota's total production.

The oil boom has erased the tribes' more than $100 million in debt and dramatically reduced an unemployment rate that was once as high as 70 percent. But many tribal members — Fox included — have been concerned about the impact of rapid land development.

Incidents — such as this summer's pipeline break that spewed more than a million gallons of saltwater into the reservation's rugged badlands and past discoveries of illegally dumped radioactive filter socks — have prompted calls for additional environmental protection.

"What was being pushed on the tribe was that if we didn't get on that train we were going to miss out," Fox said in an interview with The Associated Press on Friday. "We've got to get away from that mentality for our peoples' sake because when this oil is gone ... this is still our home."

Williams is not advocating a slowdown in development, but said additional regulations need to happen.

"We need to take an approach that's really about protecting the whole reservation and may include partnerships with state and local authorities because pollution knows no boundaries," he said.

Ron Ness, head of the North Dakota Petroleum Council, said while the change in tribal leadership may result in policy shifts, his group expects to have a positive relationship with the new chairman.

"By and large we expect to have a good working relationship and get the state and tribe working toward unified regulatory policy," he said.