DEA agents busted a Colorado grow-op that was legally growing marijuana under state law, but smuggling the weed to states where it is still illegal. Late last year, DEA agents, assisted by a local SWAT team, raided the property of Michael Stonehouse and seized around $5 million of marijuana which he was reportedly smuggling out of state. This March, Stonehouse and 15 others were arrested in connection with the smuggling operation.

The investigation began last August, when federal and local agents found makeshift marijuana greenhouses disguised as a tomato cultivation site. Stonehouse showed agents that he had a medical marijuana patient registration, but it did not cover the vast amount of marijuana that was being grown on his properties. “The Stonehouse organization had many licenses, but that was likely just to present the appearance of compliance with Colorado law,” said Paul Roach, supervisor of the DEA’s Denver financial investigations team.

The Stonehouse operation is reportedly not an uncommon occurrence.  In 2015, the Colorado State Patrol made 394 seizures of locally grown pot intended for shipment to 36 other states, according to a 2016 report by the Rocky Mountain High Intensity Drug Trafficking Area. Law enforcement authorities have said that individuals running illegal grow-ops in other states have moved to Colorado to grow legally, but maintain their illegal distribution networks in their home states.

These operations “get appropriate paperwork, but they are going to grow as much as they can and all of the excess is going out of state,” Denver Drug Enforcement Administration spokesman James Gothe said. Colorado-grown marijuana is becoming more popular than Mexican pot on the black market, due to its higher quality.