Research Update: Cultivating a Potential Ecological, Economic and Social Disaster

January 1, 2014, Department, by Kelly S. Bricker, Matthew T.J. Brownlee and Jeffrey N. Rose

Federally managed lands (i.e., the National Park Service [NPS], United States Forest Service [USFS], Bureau of Land Management [BLM], etc.) serve a variety of purposes, including sustainable use (recreation, timber, etc.) and conservation. A pressing threat to these lands is illegal and rampant marijuana cultivation (Marijuana sativa). Although this issue is not new among the many challenges facing public lands, in 2012 the United States Attorney’s Office (USAO) stated that illegal drug production on public lands “pose[s] a safety threat to the public and an environmental threat to the land and to wildlife, [and that] the problem is severe” (USAO 2012). This declaration is partially attributed to the substantial increases in marijuana cultivation on public lands in the last two decades. For example, marijuana plants seized annually on public lands increased from less than one million in 2004 to 2.6 million in 2009. Within a three-year period, 49,105 metric tons of marijuana were confiscated on California’s public lands alone (Miller 2012).

As a result of these increases, recent eradication efforts have resulted in more than $1.45 billion in marijuana seizures on public lands across seven western states. During the summer of 2012, approximately 67 percent of all marijuana plants captured in the west occurred on public lands (USAO 2012). However, successful seizures represent as little as 15 percent of estimated production efforts on public lands (National Drug Intelligence Center 2012). These data reveal the enormity of an issue that often under-resourced land-management agencies must constantly confront. Consequently, marijuana cultivation threatens the sustainability of public lands, causing grave ecological, economic and social impacts. 

Ecological Impacts

To increase production capacity, marijuana growers often expose sunlight and clear arable land by removing endemic flora that land managers aim to protect. Furthermore, individuals involved in marijuana cultivation often divert streams to irrigate their crops and frequently introduce harmful rodenticides and insecticides indiscriminately. As a result, these toxic products contaminate local watersheds by polluting streams and damaging sensitive riparian habitats (Murphy 2001, National Drug Intelligence Center 2005). Additionally, cultivators reside at grow sites for extended periods of time and irresponsibly dispose of household litter, human waste, irrigation lines and large stores of federally banned fertilizers (USAO 2012). 

Economic Impacts

Economically, near-park communities often have high reliance on well-managed public lands (Eagles and McCool 2002), and this reliance can be jeopardized by marijuana cultivation. For example, some visitors or commercial operators may be discouraged from using a specific protected area due to the presence and perceived danger of illegal activity. The economic impacts stretch well beyond near-park communities, as cultivation activities place unforeseen burdens on many agencies’ budgets. For example, the National Park Service estimates that for every acre of marijuana cultivation, approximately 10 acres is damaged with an estimated restoration cost of $11,000 per acre (National Drug Intelligence Center 2005). 

Social Impacts

Land managers are charged with public safety and visitor enjoyment (Manning 2012), and marijuana production on public lands conflicts with this mandate. Often, heavily-armed individuals secure and booby-trap grow sites, and drug traffickers transport the marijuana after cultivation, posing additional threats to residents in near-park communities. Additionally, some professionals suggest that growers may not voluntarily engage in cultivation and could perhaps be coerced and threatened to participate by organized crime syndicates (Beckley 2010). 

Research Initiative

Given that this issue impacts the sustainability of public lands, we are exploring the challenges and complexities of illegal marijuana grows therein. To date, we have conducted semistructured interviews with 18 professionals from NPS, USFS, BLM, USAO, the Bureau of Indian Affairs (BIA), the Department of Justice (DOJ) and the National Marijuana Initiative (NMI). The interviews included individuals from diverse departments, such as law enforcement, public affairs, ecology, administration and resource management. 


Examples of Supporting Quotes



“Different federal agencies don’t talk.  Within this region there are XX DEA offices, XX forest districts, XXX divisions, and not each division will take the same stance on marijuana. Here we make it the feather in our cap, but XXX says they don’t care and then someone else can run the show [responding to cannabis cultivation on public lands]… Just not aggressively pursuing it with the same tenacity, even within one agency, much less with a lot of agencies working together.”


“We’ve got to have the resource people talking to the law enforcement folks. And then we try to communicate our operations to other folks in the Forest Service, because they’re dealing with these same issues.”

Beyond agency

“We need to join the federal land management people with the university people. People are truly engaged but are 3,000 miles away in many cases, and out of the field, and don’t even know who is working on this.  Having research to support taking it to the Hill, real research documents to say this is really what’s going on out there and why…”

The Grows

Dynamic production tactics

“These grows are no longer Mom and Pop operations… 20 years ago, it was small cultivation operations. Parks that historically had no connections to local (drug) areas have experienced marijuana growth on a scale of not 5 or 10 plants, but hundreds of thousands of plants… The nature of it has changed to a sizeable operation, greater sophistication than one can do on their own [sic].”

Law enforcement investigations

 “There has been a bigger emphasis placed on the investigation side. We’re trying to tie it all together…getting people camping at the grows, means nothing.”

Ancillary Challenges


“Visitor safety is our number one priority, but I worry about our rangers also …99 percent of the grows I go into I find weapons.”

Challenge to resources

“We need a new model, we are public land managers, not international drug cartel enforcement officers…these are complex and different from what we are trained to do.”

Removal of infrastructure

 “One of the market disruptions we look at is we have to remove the infrastructure. If we don’t, many of the growers will come back within the same grows the following year and use the facilities that have been left behind. That is why for reclamation we now remove everything in the grow site, trash, piping. If we leave that stuff, it takes minimal effort to get the grow site up and running again.” 

Ecological Impacts

Known and unknown

“One of the challenges is the support from the public and support from the Hill as to what the environmental impacts actually are, and the biggest challenge is being able to educate everybody…that it’s a huge impact related to public lands. What we need to do better and what a lot of people don’t know is the environmental impacts.”

Known and unknown

“We really don’t know, I mean, we don’t know about water quality… some of the wildlife issues, clear cutting issues.  It’s a big deal…


Resource degradation

“There was a complete disconnect of management with law enforcement—they were flabbergasted that this was occurring [toxins in the environment] – completely unaware of [ecological impacts], of magnitude of what is going on out there…”

Interagency involvement

“You’re dealing with multiple jurisdictions, multiple experience levels, some people are talking to each other, working together…”

Future Concerns

Ambivalence -ambiguity of legality

 “Whatever happens [with legalization], we’ve got a job to do. So legalization isn’t a question for us. You’re not allowed to grow corn or potatoes in national parks, so we would go after those grows too.”

“There will still be a market for it, because there’s always a black market for something. It’s not real clear how it [legalization] will impact public lands.”

Uncertainty on success

“Not sure we’ve made any headway…”


Assembling the Stakeholders

The authors are hosting a symposium in March 2015 at the University of Utah in Salt Lake City, which will assemble stakeholders such as land managers, park and recreation professionals, restoration ecologists, public health and law enforcement personnel, and researchers who address marijuana cultivation on public lands. 

Currently, managers need an integrated and comprehensive outlet to explain and share their challenges and successes. Agencies consistently report that a symposium that brings professionals together to understand the issue and each agency’s practices would substantially increase their ability to address marijuana on public lands. We hope that through this symposium we can begin to address the complexities of this issue. Symposium topics will:

  • Distill best practices and institutional challenges regarding marijuana on public lands;
  • Highlight specific drivers that prohibit, assist and influence the prevention, mitigation and response to marijuana on public lands;
  • Compare and contrast challenges across different land-management agencies and positions regarding the issue;
  • Produce a communication tool for agencies to relay their challenges aimed at garnering political and financial support to address marijuana on public lands; and
  • Renew political commitment for addressing this growing issue.

For more information, contact Kelly Bricker.

Kelly S. Bricker is an Associate Professor and Matthew T.J. Brownlee is an Assistant Professor in the Department of Parks, Recreation and Tourism at the University of Utah. Jeffrey N. Rose is an Assistant Professor in the Department of Environmental Studies at Davidson College.


Beckley, B. (2010). Keeping safe if you come across a marijuana grow site. In  Safety and Health Law Enforcement & Investigations, USDA Forest Service. Retrieved December 4, 2012.

Eagles, P.F. & McCool, S.F. (2004). Tourism in National Parks and Protected Areas. CABI Publishing, New York, New York.

Manning, R.E. (2012). Studies in Outdoor Recreation. Corvallis, Oregon: University of Oregon Press.

Miller, C. (2012). Public Lands, Public Debates. Corvallis, Oregon: Oregon State University Press.

Murphy, K. (2001) Washington state forest closed after discovery of meth lab. San Francisco Chronicle, May 26, B12.

National Drug Intelligence Center. (2005). Marijuana and methamphetamine trafficking on federal lands threat assessment. U.S. Department of Justice. Accessed September 10, 2012.

United States Attorney’s Office. (2012). US attorneys announce final statistics on operation Mountain Sweep. United States Attorney Benjamin B. Wagner, Eastern District of California. Accessed September 15, 2013.