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Illegal cannabis grows on CA public lands, known as “trespass grows”, constitute one of the leading issues threatening California’s wildlife, communities, and public land users. Trespass grows, 90% of which are controlled by drug trafficking organizations, contain copious amounts of illegal pesticides and herbicides that contaminate water, poison wildlife and people that come in contact with these grows, threaten tribes and disadvantaged communities dependent on natural resource economies, and reduce access to public lands for jobs, gatherings, and recreation.  Arguably, illegal cannabis production on public lands may be the largest near-term threat to native species, communities, and ecosystems in much of California.

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The Humboldt marten, and ESA-listed species, and the Pacific fisher, a candidate species, were proposed for listing partly as a function of trespass grow toxicants. Second-generation anticoagulant rodenticides  (SGAR) are a pesticide found in excess at and near trespass grows, and research has shown that now 95% of Mountain lions, 85% of fishers, and 70% of Northern Spotted Owls (ESA listed) have been exposed. Biologists conservatively attribute the deaths of many hundreds of predators, including black bears, bobcats and raptors to banned Bromadiolone and Brodifacoum, common SGARs. 

North Fork Trinity River, Trinity Alps 

Key native fish streams are dewatered to irrigate cannabis grows, accelerating the demise of endangered fish such as Coho salmon and Steelhead. It is estimated that trespass grows across the state divert a total of 9 billion gallons of water annually-- enough annual water for the entire City of Redding. Lacking regulatory oversight, these grows are a clear and present threat to ecosystems, communities, and users of public land.

The primary goal of the CROP Project is to greatly increase the state and federal resources to remove trespass grows on the national forests of Northern California. Our first and second objective is to secure funding for local NGOS and tribes to reclaim sites, and to place more Forest Service law enforcement on-the-ground to help prevent the activation of new sites. This will effectively reduce exposure rates of toxic pesticides and insecticides to communities downstream or near trespass grows, users of public land, as well as wildlife poisonings. The third goal of the project is to increase criminal penalties for those bringing toxicants onto public lands. 




  • 60% of all water in California originates from National Forests (NF)

  • An average outdoor cannabis plant consumes 600-1200 gallons/yr

  • More than 9 billion gallons of water annually are illegally diverted for trespass grows, or 27,600 acre feet (enough for nearly 30,000 homes)

  • Decreased water for downstream deliveries to Tribes and communities

  • Decreased water for fisheries and timber production

  • Watershed diversion from trespass grows can account for 23-50% of total surface flow 

  • CA has 45 million acres of public land, including 20 million acres of National Forest (NF) 

  • 40-70% of CA's illicit market is from trespass grows

  • Over 1/3 of total CA production is on NF

  • 52% increase in illicit production on NF in 2016

  • Law enforcement estimates only 1 in 5 plants are eradicated annually

  • 3 million plants eradicated from NF since 2016-2018

  • 23 million plants eradicated from NF 2000-2018

  • In 2018, 90% of reclaimed trespass grows contained illegal, highly toxic pesticides

  • Use of highly restricted, and often banned, neurotoxic Bromodialone rodenticide and Sarin based Malathion in extensive use on trespass grows

  • Many animals tested in the vicinity of grow sites show up to four toxic compounds in their blood

  • 80% of Pacific fishers tested in California's national forests have high levels of rodenticide

  • 22 radio-collared fishers found dead from rodenticide and Sarin poisoning

  • 100% of Pacific fishers in Plumas National Forest tested positive

  • 85% of Mountain lions statewide have high levels of rodenticide

  • 80% of Barred owls tested in 4 NF have high levels of rodenticide

  • 70% of Spotted owls tested in 4 NF have high levels of rodenticide

  • 100% of benthic invertebrates show high levels of toxins in Plumas and Tahoe national forest streams

  • Extensive dewatering of streams leading to extensive mortality of anadromous and other native fish, most listed under the Endangered Species Act

  • Substantial but unknown mortality of black bears, bobcats, coyotes, martens, mountain lions and other predators from intentional poisoning or from consuming contaminated wildlife


Trespass Grow Facts
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Cannabis Industry Support
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