California produced at least 13.5 million pounds of marijuana last year — five times more than the 2.5 million pounds it consumed.
Where did all that extra pot go?
The answer, experts say, is that much of it ended up in other states — some where marijuana is still illegal.
As California prepares to allow cannabis sale for recreational use, that surplus has become a problem.
"If we want to avoid intervention from the federal government, we need to do everything we can to crack down on illegal activity and prevent cannabis from being exported out of state," Assemblyman Tom Lackey (R-Palmdale) said.
The wide gap between production and consumption came to light in a recent study commissioned by the state Department of Food and Agriculture.
Marijuana is an illegal drug under federal law, and U.S. Atty. Gen. Jeff Sessions has said he favors stricter enforcement. Under the Obama administration, the Department of Justice had placed a lower priority on enforcing the law in states that allowed medical marijuana.
States interpreted a 2013 memo by then-Deputy Atty. Gen. James Cole that they could avoid federal intervention as long as they tried to stop serious marijuana crimes, such as sales to minors, gang sales and exports to other states.
The new California Bureau of Cannabis Control is scrambling to put regulations in place to begin issuing state licenses to grow, transport and sell marijuana starting Jan. 2. Those rules explicitly prohibit the export of marijuana to other states.
Lackey, a retired sergeant for the California Highway Patrol, introduced legislation last month naming the CHP as the lead state law enforcement agency investigating black market cannabis.
Currently, no agency in the state runs point on drug enforcement. It's policed by a combination of city and county law enforcement and the state Bureau of Narcotic Enforcement.
Lackey said his bill, which will be debated early next year, will help stop the export of marijuana.
The measure will be considered when the Legislature returns in January.
Law enforcement officers in places like Texas are worried about California's exports. A spokeswoman for the Texas Department of Public Safety said Interstate 40, which spans from East to West Coast, "has become a major drug corridor."
In one 48-hour period in early August, highway troopers stopped three vehicles from California on the same stretch of Interstate 40 east of Amarillo, seizing $2.5 million worth of marijuana.
First came 60 pounds of marijuana worth $364,000, smuggled inside a Dodge Caravan driven by a man from Eureka, heading to Memphis, Tenn.
State troopers also confiscated 69 pounds of marijuana worth $418,000 from a minivan being driven to Tulsa, Okla., by a woman from Phelan, Calif.
Three hours later troopers seized 300 pounds of marijuana worth $1.8 million from another minivan heading east. They arrested a woman who allegedly was driving the drugs from Fresno to Tulsa.
"Any amount of marijuana coming out of California and going through our state is a problem because it's not a legalized drug in Texas," said Lt. Bryan Witt of the Texas Department of Public Safety. "If we catch anybody with any amount from California, they will be arrested. Our marijuana laws will be enforced."
California officials say they plan to impose regulations to keep pot off the black market and ensure that marijuana offered for sale is safe. But leaders of the marijuana industry remain concerned the surplus will still need to be addressed.
"We are producing too much," Hezekiah Allen, executive director of the California Growers Assn., said at a recent conference on marijuana.
Allen said state-licensed growers "are going to have to scale back," and are "on a painful downsizing curve," adding that some farmers are going out of business while others are preparing to reduce crops under the new legal system.
Lori Ajax, executive director of the state pot bureau, said she's concerned that some marijuana growers will not get state licenses and remain in the black market.
"For right now, our goal is to get folks into the regulated market — as many as possible," Ajax said.
The Drug Enforcement Administration already has focused much of its efforts on California. Federal, state and local law enforcement agencies reported seizing 5.3 million marijuana plants throughout the nation last year. Seventy percent were confiscated in California — more than 1 million more plants than were seized in the state a year earlier.
That far surpassed No. 2 Kentucky, where about 500,000 pot plants were seized in 2016. The law enforcement actions in California last year involved 2,117 growing sites and resulted in 2,002 arrests, compared with 861 sites raided in Kentucky, where there were 691 arrests.
California, the most populous state in the nation, has good growing weather for pot and vast areas of backcountry where farms can hide.
If the new regulated system in California does not make a dent in exports, more federal action is likely.
"I think you will see the DEA get a lot more aggressive" in responding to marijuana exports by states allowing recreational use, said DEA agent Melvin Patterson, a spokesman for the agency. He added that such cases will be aggressively prosecuted.
California officials have come up with ways to prevent marijuana from state-licensed farms from becoming illegal exports. Ajax said her agency will require seed-to-sale monitoring in which every plant is given a tracking number that will allow officials to make sure it stays in the state and is properly sold.
Ajax also has said it is important that the state's regulations and taxes not be such a burden on growers and sellers that they are driven into the shadows.
ERA Economics, which conducted the study on production and consumption, warned that strict regulations and high taxes and fees will "push cultivators into the illegal markets" unless there is strong enforcement.
Colorado, Oregon and Washington, which have legalized recreational use, are facing the possibility of more federal enforcement, according to a new report by Smart Approaches to Marijuana, which opposes legal weed.
"I don't think California lawmakers realize how difficult it is to put proper safeguards in place," said Kevin Sabet, president of SAM. "Right now, the posture in Sacramento seems to be tilted at allowing whatever the pot industry wants."
State officials, including Assemblyman Ken Cooley (D-Rancho Cordova), who has introduced bills to regulate pot, say they are aware of the risks and have tried to create a system that will limit illegal activity.
"If the feds see a serious export problem ... they might feel that whatever we are doing in California is not enough," Cooley said.