Today, illegal cannabis cultivation on public lands is one of the worst marijuana-related problems in the United States. Since the 1980s, outlaw marijuana growers have dumped millions of pounds of plastic and other trash into public forests, poisoned wildlife with pesticides and fertilizers, siphoned water from streams, clear-cut trees, and posed a threat to visitors and authorities alike with booby traps and guns.

Though it is most heavily concentrated in California, illegal marijuana growing occurs (and has occurred) on public land all over the country. Over the last several decades, state and federal law enforcement have fought public-land marijuana with varying levels of resources and intensity; yet the trend has only intensified. States such as California and Colorado have legalized marijuana, but that, too, has failed to curb the plant’s illegal growth on public lands.

Why is this? Is there any solution to the problem of pot growth on our public lands? As it often does, the past provides us with some critical perspective on this issue.

Origins

Marijuana cultivation on public lands was almost unheard of before the 1970s; most of the dope smoked by hippies and other American aficionados came from Mexico. But when US President Richard Nixon officially began the War on Drugs in the early 1970s, it became much riskier to transport large amounts of marijuana over the southern border. By the mid-1970s, under the Ford Administration, the federal government helped Mexican authorities spray Mexican marijuana crops with Paraquat, a toxic herbicide. Pot smokers in the United States became paranoid that their stash may be contaminated, and countercultural publications like Denver’s Straight Creek Journal ran numerous articles about the possibility of paraquat-laced pot.

American and Mexican authorities’ new focus on drugs at the southern border and the Paraquat scare had the effect of making domestic marijuana—long thought to be an inferior product—far more marketable. At the same time, a countercultural migration known as the back-to-the-land movement was spreading out into sparsely populated areas across the country, especially in northern California and southern Oregon. Back-to-the-landers were mostly young, well-educated, white, middle-class people seeking to simplify and purify their lives by getting back in touch with nature and living off the land. For many, marijuana use was a normal part of their social, recreational, and spiritual lives.

Back-to-the-landers soon realized that growing marijuana not only provided them with their own personal supply but also gave them a fine opportunity to make ends meet. In many places, especially northern California and southern Oregon, domestic marijuana became a cottage industry, supporting homesteads and communities and increasingly drawing back-to-the-landers away from their simple lives and into the risky but profitable arena of black-market capitalism.

Law enforcement took note of this new, increasingly profitable industry and began staging raids on growers throughout the 1970s. When Ronald Reagan won the White House in 1980, he intensified the War on Drugsacross the country, funneling federal resources to urban areas to combat crack use and into rural areas to fight marijuana growers. Authorities all over the country began arresting more growers, pushing up the price of weed and driving growers indoors or into remote spaces on public lands.

California: A Case Study

In California, a conservative state government partnered with the Reagan Administration in 1983 to create the Campaign Against Marijuana Planting (CAMP), an annual cooperation between dozens of state and federal agencies to eliminate marijuana cultivation in California. Unique to California, the CAMP program remains active today, and data from its past reports offer insight into the trend of marijuana growth on public lands.

In California, marijuana grown on public lands accounted for about 30 percent or less of all pot plants seized in CAMP raids during the 1980s—roughly 400,000 plants. That percentage dropped to 11 by 1994, but then increased dramatically after 2000 (CAMP data from 1997-99 is not available). Meanwhile, the estimated price per marijuana plant ballooned from just over $2,000 in 1983 to around $4,000 by the 2000s.

Why did marijuana growing on public lands intensify after 2000? In addition to high prices, one reason was the legalization of medical marijuana in eight states between 1996 and 2000. Seven of those eight states were Western states with large tracts of public land. Using the plant’s new, semi-legal status as cover, hundreds of outlaw growers began setting up in National Forests, especially in California. By 2009, 76 percent of marijuana seized by CAMP—nearly 340,000 plants—was taken from public lands. That same year, BLM and Forest Service officials reported large-scale marijuana cultivation on public lands in Colorado, Oregon, and Idaho. In 2010, “nearly 60 percent of the outdoor marijuana plants eradicated” by federal authorities across the United States came from public and tribal lands; most of those plants were grown in California.

Increased enforcement in Mexico is likely another reason why American public lands attracted more pot growers after 2000. Mexican authorities cracked down on marijuana cultivation under President Vicente Fox (2000-06) and made record levels of drug arrests under President Felipe Calderón (2006-2012). These trends undoubtedly encouraged at least some Mexican cannabis growers to head north onto US public lands.

In the 2000s, CAMP reports increasingly included references to growers who were “Mexican Nationals” and part of “Drug Trafficking Organizations,” or “DTOs.” Although CAMP stopped short of using the word “cartel,” that did not prevent other authorities in California from assuming that violent Mexican cartels were taking over America’s public lands. But as late as 2011, it simply wasn’t clear how many public-land grows run by Mexican citizens were actually linked to DTOs, and whether those DTOs were actually linked to larger cartels.

The Solution: Legalize

Looking at this abridged history of marijuana growing on America’s public lands, two key points stand out.

First, increased enforcement has not discouraged cultivation on public lands; rather, it has only driven up and sustained the price of marijuana, which encourages larger and more irresponsible cultivation.

Second, although growing pot on public lands has had disastrous ecological effects in California, it has never quite gotten to that level in other states; even in 2015, with prohibition still driving a lucrative black market, California had twice as many grow sites on public lands as the state with the second-most, Kentucky. So really, most of the nation’s 640 million acres of public land are pot-free, despite what federal officials and mediareports would have us believe.

Still, we don’t need more situations like California’s popping up, and the forests of the Golden State desperately need a reprieve. Fortunately, the solution is staring us in the face: the United States needs to legalize marijuana. Federal officials like to hold legal-marijuana states to the fire for ongoing black-market activity, but the government’s own policy is largely to blame for that: if marijuana was regulated everywhere, there’d be no reason for outlaw growers to congregate in a few states.

Journalists, scientists, environmental historians, and even former forest rangers have all argued that legalization will help our public lands; the question remains whether federal agencies such as the US Forest Service and Bureau of Land Management will take up the cause. After all, these agencies have plenty of other problems on which to spend their limited and dwindling resources. Marijuana—especially in the age of legalization—should not be one of them.

– Nick Johnson