The first indictment in a North Dakota drug investigation made public on Monday shows federal charges against 22 people for conspiracy to sell heroin and other drugs, the Associated Press reports.
Investigators say that drugs were allegedly brought into the Fort Berthold Indian Reservation, located within the Bakken oil patch southeast of Williston, from other parts of the country.
According to the indictment filed in March, the defendants are accused of dealing heroin and methamphetamine on and around the reservation, KQCD reports.
Williston, the fastest-growing metropolitan area in country as a result of people looking to work in the oil industry, has seen stepped up police enforcement since the oil boom began, the Associated Press says.
Investigators believe increased heroin sales in the state are likely due to the abuse of prescription painkillers because the illegal substance is cheaper than the alternative.
The Three Affiliated Tribes, a Native American group comprised of the Mandan, Hidatsa and Arkian people, budgeted $1 million for a drug task force initiative to combat the addiction "epidemic" plaguing the reservation, the Minot Daily News reported.