Colorado state police, partnered with local law enforcement, raided 40 illegal weed grow-ops this summer, seizing and destroying nearly 6,000 cannabis plants in the process.

The operation, led by the Las Animas County Sheriff’s department in cooperation with the Colorado Bureau of Investigation, Colorado Parks and Wildlife, and other local law enforcement, led to the seizure of 5,904 illegally-grown pot plants, valued at around $5.8 million.

The series of raids was triggered by an attempted shooting that occurred early this spring. A rancher in Otero County told police that unknown suspects shot at his 13-year-old son while he was rounding up cattle. Police tracked the suspected shooters down to two nearby black market weed grows. Cops raided these grows, arresting four suspects and seizing 486 pot plants and six guns.

Following the success of this raid, police doubled down on other suspected grow sites in the county. Near the New Mexico border, cops raided three illegal grows, where suspects had planted between 5,000 and 15,000 plants. Authorities discovered that the plants had been grown using Carbofuron, a toxic pesticide that can cause respiratory paralysis and death.

Gallery — Fuck-Tons of Weed That No One Is Smoking Besides Cops:

Many illegal pot growers use dangerous, federally-prohibited pesticides like Carbofuron on their plants to save money during the cultivation process. These pesticides leave toxic residue behind, which has been known to poison plants, wildlife and waterways. Indeed, authorities discovered a dead bear cub on one of the sites, most likely poisoned by pesticide residue. Colorado Parks and Wildlife is now tasked with safely removing the plants and chemical residues from these sites.

Cops conducted one final raid in the Fishers Peak Ranches Subdivision, seizing 364 plants from two sites and arresting one suspect in connection with the grows.

These raids are part of a concerted statewide effort against Colorado’s thriving black market. The state’s original adult-use law allowed any individual to grow 99 weed plants each, and relaxed regulations allowed legal businesses to grow far more weed than Colorado tokers could ever possibly consume. Stuck with more product than they could legally sell, legal and private growers alike began diverting excess weed to the black market.

Last year, federal authorities stepped in to help the Boulder State keep its weed oversupply in check, partnering with state and local authorities to raid illegal grows. This May, cops seized over $3 million worth of black market pot from the Denver metropolitan area, and in January, cops shut down a local dispensary chain for diverting their excess weed to black market smugglers.