A dozen armed officers with the U.S. Forest Service, local sheriff’s office, and other agencies teamed up with Dr. Mourad Gabriel to seize and dismantle an illegal marijuana grow site near Redding, California.

At this site—just off Route 36, east of Redding, and down a rocky forest valley—more than 4,000 marijuana plants grow beneath sugar pine and Douglas fir. There was also a campsite with several tents, two cisterns, and hundreds of feet of irrigation pipe.

Hundreds of illegal marijuana grow sites are discovered on California’s national forests each year. For the last six years, dangerous pesticides have been found at many of these sites and have impacted local wildlife.

Growers often use pesticides, some of them banned and highly toxic, to protect the marijuana plants and their camps from insects and animals.

Watch as National Geographic captures video of what illegal marijuana growing is doing to our public lands and forests.