August 22, 2025 – National Park Service officials announce law enforcement rangers, in cooperation with special agents from the Bureau of Land Management, removed an illegal marijuana cultivation site in Sequoia National Park last week.

A total of 2,377 full-grown marijuana plants and approximately 2,000 pounds of trash and infrastructure were removed by hand and helicopter sling-load operations. The site also contained a semi-automatic pistol and several hazardous chemicals, including about one gallon of Methamidophos, a highly toxic insecticide banned in the United States since 2009.

Law enforcement rangers detected and raided this cultivation site in 2024, but the site was not rehabilitated until this year due to the presence of hazardous chemicals. No arrests have been made, and the investigation is ongoing. Please call the NPS-wide Tip Line at 888-653-0009 with any tips on illegal cultivation on park land.

Damage to the approximately 13-acre area includes: 

• Diversion of the natural flow of water from a nearby creek and installation of irrigation lines   

• Construction of several large pits to store diverted water from a nearby creek  

• Significant clearing of natural vegetation 

• Digging of terraces into the hillside for planting of marijuana 

• Development of campsites, kitchen areas, and cultivation sites in a wilderness area 

• Evidence of poaching activity 

• Illegally maintained trails covering approximately two miles 

Large marijuana cultivation sites can have major impacts on the Central Valley. According to the California Department of Fish and Wildlife, a single marijuana plant uses six to eight gallons of water a day that would otherwise nurture wildlife and vegetation. In addition, water for personal use (drinking, bathing, cooking, etc.) and for crop irrigation travels from the mountains within Sequoia National Park to areas of the Central Valley. Runoff from large cultivation sites may be tainted due to the large variety of pesticides that are used in growing marijuana.   

For almost two decades, well-organized drug-trafficking organizations have been operating large-scale cultivation operations in and around Sequoia and Kings Canyon National Parks. These cultivation sites cause major damage to the parks’ natural resources and are a threat to public and staff safety. In the last 20 years, nearly 300,000 plants with a value of almost $850 million have been eradicated in Sequoia and Kings Canyon National Parks. 

Pictured: 1. A federal law enforcement ranger at the illegal marijuana cultivation site. 2. A helicopter sling-load carries out trash from the illegal marijuana cultivation site. 3. An aerial view of the illegal marijuana cultivation site.

Source & photos: NPS