A two-week multi-agency effort led by the Yurok Tribe eradicated about 55,000 cannabis plants on and near the Yurok Reservation in July 2015.[1][2] Officers served 30 search warrants, arrested seven people, seized 1,000 pounds of processed cannabis and uncovered one hash-oil lab.[2] The tribe said the main purpose was returning as much water as possible to the Klamath River and the community water systems downstream of the grows.[1]

The plantations were diverting millions of gallons of water from creeks feeding tribal water systems serving more than 300 families, while the Klamath ran warm enough to threaten migrating salmon.[3] Raided sites held abandoned vehicles, broken batteries, household waste, chemical fertilisers and illegal grading that one scientist at the scene called an environmental disaster.[3]

Tribal leaders called the grows the largest ever seen in their territory and promised charges for every environmental crime.[3] The tribe had run a similar operation the previous year, and its vice-chair said the raids would continue every summer until growers left the area.[2]