Trevor Hughes

USA TODAY

WILLOW CREEK, Calif. — Sgt. Kerry Ireland leans out the open door of the circling helicopter, his hand pointing down at the emerald-green plants growing in neat rows beneath a canopy of trees.

“There you go, there’s one,” he yells over the thumping blades and whistling wind as the pilot holds the ship in a tight turn.

Deep in Northern California's national forest and miles from the nearest paved road, someone has illegally planted hundreds of marijuana plants. In the helicopter’s rear seat, Deputy Kyle Holt checks the GPS tracker in his lap to make sure the coordinates match the location, and they fly off in search of the next illegal grow. And the next.

They're flying all day, but there are so many farms they could do this all summer long — finding spots of land cleared for cannabis cultivation that pockmark thousands of acres of forested mountains.

While these helicopter flights are an annual exercise for Ireland and his team, this year they're bringing along something new: a recently enacted county law requiring cannabis growers to meet tough new regulations of the kind normally followed by traditional farmers and business owners.

Long before it enters the consumer market, pot grown by illegal operations — often on public land — is leaving deep marks on California's already stressed landscape. Redwood and pine groves are scraped bare by bulldozers, and ponds turn green after over-fertilized water feeds algae blooms. The large, hidden farms tap already low rivers, dirty the drinking water and pollute important fisheries.

In a sparsely populated county nearly the size of Connecticut, many marijuana growers decided the risk of getting caught is worth the profits. The damage has grown more severe over the past several decades as commercial-scale operations elbow out smaller, family-run operations, officials say.

As a result, law enforcement is trying a different tack to fight illegal pot grown in Humboldt County, the source of most of the cannabis flowing through California's massive marijuana industry. Rather than just using criminal laws, town and county police officers have started to wield environmental laws to curb this activity.

“The problem we have to address are the people who have no care for the environment, and I would argue, no care for their community," said Estelle Fennell, a member of the county’s elected Board of Supervisors. "They’re just in it for a buck.”

Cops and code inspectors

California has the country’s largest medical marijuana marketplace, with billions of virtually tax-free dollars flowing from growers to distributors to co-ops that operate on a “donation” system. Drivers then deliver high-quality pot to customers' homes or offices, within minutes.

The system gives growers and users a level of legal protection from state criminal laws that would otherwise make possession of large amounts of pot a felony. And as in other states, including Colorado, many growers use the cover of the medical marijuana system to grow cannabis they'll then illegally ship across state lines.

Some of the Humboldt County industry is legal, at least under state law. Much is illegal. And all of it violates federal law.

Frustrated by their inability to make a significant dent in the flow of illegal pot, police and regulators in Northern California are increasingly turning to environmental and zoning laws. The fact is, few marijuana growers bother to comply with basic rules governing electrical wiring, construction permits or water supplies.

The violations are glaring. Pot growers steal water, illegally cut down and clear forested areas, build unpermitted greenhouses and dump massive amounts of fertilizer on their crops, police say. Now growers find themselves targeted by cops accompanied by code inspectors. While criminal cases can take months or years to wend their way through the court system, civil violations are far easier to prove.

“Taking that route is what’s really going to hurt them,” Ireland said. “The majority, the vast majority, only cares about making money.”

Single bust: $26M

Looking around Humboldt County, it’s easy to see how marijuana money drives this economy, from the high number of fertilizer dealers to the stores selling equipment to trim the plants for sale. One estimate from a local banker said fully 25% of the entire county economy is marijuana-related.

“You can’t swing a dead cat in Humboldt County without hitting a major marijuana operation. It’s everywhere in Humboldt County,” Ireland said. "Everywhere."

Marijuana occupies a gray area in Humboldt, which has just 37 residents per square mile. State law allows people to grow cannabis for medical use, or grow it on behalf of others. There’s no real statewide central registry of who is allowed to use or grow medical marijuana, which means police trying to keep things legal have to wade through stacks of paper authorization forms, which may be photocopies shared by multiple growers.

The potential profits are staggering: In Humboldt County, a pound of processed marijuana sells for about $1,500. Sold illegally in another state that same pot could be worth two or three times as much. And even the worst grower can get a half-pound from a plant, while an expert can easily coax upwards of 3 pounds, police say.

The Humboldt Country Drug Task Force arrested one man this year found with more than 2,000 marijuana plants. That’s a haul worth at least $1.5 million. Last year, deputies made a single bust worth $26 million, seizing 23,000 plants, more than 2 tons of processed pot and 50,000 rounds of ammunition.

“Marijuana is the cash crop of Humboldt County. It’s what people do there,” said Emily Brady, author of the book Humboldt: Life on America’s Marijuana Frontier.

Hippies founded the local marijuana industry, many moving out of San Francisco during the 1960s back-to-the-land movement. Today, those aging hippies and their descendants compete with large-scale growers who illegally bulldoze forest areas to make farms hidden from view — or at least hidden from the ground.

From the air, it’s clear that Ireland and his team have their hands full. On a flight funded by the U.S. Forest Service, Ireland identifies dozens of potentially illegal marijuana farms scattered in the mountains near Eureka . While Humboldt County’s marijuana is legendary for its quality, the terrain doesn’t lend itself well to farming. Trees cover the steep hillsides, and getting supplies from town can mean hours of driving. And forget about getting access to legal irrigation water in many places. If growers want water, they often just steal it from rivers, police said.

“It’s basically been unregulated agriculture,” Brady said.

'Long view'

Using environmental and business-regulation laws to fight these operations has local lawmakers hopeful. But even with better tools at hand, they face the daunting and possibly insurmountable challenge of better-funded growers.

The new county rules, authorized by a broader statewide law, require growers to register industrial-scale cannabis operations and to comply with basic environmental regulations, the same kinds of rules that conventional farmers or orchards have to follow.

Since the country rules took effect in January, about 40 growers have completed the registration process. That’s a literal drop in the bucket, but it's a start.

“This has been an issue that’s developed over four decades. It started out as a little here and a little there but it became very businesslike. People are making a lot of money, so over time, specifically in the past 10 years, there’s been something akin to a green rush," said Humboldt County's Fennell.

Fennell said the new county rules are intended to take a “long view” of the problem and will likely take years to have a significant impact. The rules require growers to cultivate marijuana only in prime farmland, which could make most of the county’s mountainous areas off-limits.

Marijuana-industry analyst John Kagia, who visited Humboldt County this summer, predicts the county’s new regulations will only persuade a small number of growers to cooperate. Steep black-market profits will likely prove too tempting for some growers, and they’ll just continue to run the risk of getting caught, including those who illegally farm in the national forest.

“The reality is that enforcement of regulations is still going to face vast challenge, because those (black-market) growers have the least motivation to transition into the regulated market,” said Kagia, executive vice president of industry analytics for marijuana-data firm New Frontier Data.

The county hopes to slowly shift Humboldt County to a system where responsible growers are officially welcomed and irresponsible growers are forced out through a combination of targeted enforcement.

Watching from the sky as thousands of marijuana plants soak up the afternoon sun, Ireland marvels at the enormity of the task facing police and regulators. He has seen the crime that accompanies black-market marijuana. Those growers know what they're doing is illegal. Few care, he said.

“Those guys are making millions of dollars each year,” he said. “They're going to fight for what they have."

Follow Denver-based correspondent Trevor Hughes @trevorhughes