ARDMORE, Okla. (KTEN) — Over the past two-and-a-half years, agents from the Oklahoma Bureau of Narcotics have shut down around 200 illegal marijuana grow farms with ties to worldwide criminal organizations, many of which were raided this year.

"These are criminal organizations that have been around for decades moving cocaine, fentanyl, weapons... moving people, human trafficking," said OBN spokesperson Mark Woodward. "Many of them are tied to absolute violent criminal enterprises which we've tragically seen recently in a quadruple homicide."

The OBN said people from out of state started buying land in Oklahoma in 2020, and illegal grows began showing up rapidly.

"In 2021, in the spring is when they started planting, and that is when we really started seeing marijuana showing up that was being moved illegally," Woodward said.

Several dozen arrests have been made, and hundreds of thousands of marijuana plants have been seized this year.

"We work with our federal partners on these investigations to try and shut down the entire operation — not just one farm, because you really haven't made an impact," Woodward said. "They can replace those plants and workers very shortly if we don't take down the entire organization."

Twenty-five percent of licensed growers in Oklahoma are  under investigation for obtaining their credentials by fraud, or growing for the black market.

The OBN launched two units focused solely on investigating illegal marijuana grow operations.

"We were having to pull people off of investigations like heroin, meth and cocaine investigations to go take care of these tips we were getting about criminal groups running marijuana farms," Woodward said. "It's still such a strain on our agencies."