WASHINGTON — California's commercial pot growers are moving plots from national forests to Central Valley farmland, Fresno County Sheriff Margaret Mims told senators Wednesday.
Citing a "conspicuous shift" in drug cultivation tactics, Mims added that growers also are increasingly using the "guise" of medical marijuana in an effort to protect their work that, arrest records show, frequently relies on illegal immigrants.
"Rather than growing marijuana in the relative secrecy and anonymity afforded by remote public lands, many moved illicit operations onto private agricultural lands," Mims advised the Senate Caucus on International Narcotics Control, which held a hearing Wednesday on marijuana cultivation on public lands.
Fresno County has seen a drop in marijuana plots on public lands. In 2009, for instance, law enforcement investigators identified 81 marijuana-growing sites on public lands in Fresno County. In 2010, the number fell to 19. This year, only eight have been found.
While Mims called these reductions "appreciable measures of success," she warned of the flip side, which includes growing operations on Valley farmland. Last year, she told senators, 36 multi-acre cultivation sites were found on conventional farmland in Fresno County.
This year, one Fresno County farmland site devoted to marijuana was said by officials to span 57 acres.
"(The) Central Valley in particular has become a hot spot for marijuana cultivation because of the conditions there, including abundant sunlight, irrigation and fertilizer," declared Democratic Sen. Dianne Feinstein, chair of the narcotics control caucus.
More often than not, illegal immigrants supply the marijuana labor force, officials said.
In July, for instance, the Forest Service and other agencies arrested 159 individuals as part of what officials called Operation Full Court Press. The operation included sweeps through Mendocino, Glenn, Colusa, Lake, Trinity and Tehama counties in Northern California.
Roughly 95 percent of those arrested were illegal immigrants, the U.S. Forest Service's law enforcement director, David Ferrell, told senators. More broadly, Ferrell reported that illegal immigrants were caught tending 1,437 of the 2,334 marijuana sites seized on Forest Service land in California between 2005 and 2010.
"These are Mexican nationals who are running these operations," Feinstein said. "They are armed and dangerous, and we ought to go after them."
During the summer's Operation Full Court Press, in addition to 632,058 marijuana plants, officers reported seizing 38 weapons, including some assault rifles. A similar multi-agency operation last year, called Trident, resulted in 33 weapons and 432,271 marijuana plants being seized in Fresno, Tulare and Madera counties.
All told, Obama administration drug czar R. Gil Kerlikowske testified, 7.4 million marijuana plants were eradicated in California last year, primarily from outdoor growing sites.
"Our public lands have been taken away from us, and that's wrong," said Rep. Mike Thompson, D-St. Helena, Calif.
Feinstein joined Sen. Charles Grassley, R-Iowa, in pressing the case that California's allowance for medical marijuana has given Mexican-run drug trafficking gangs cover for their illegal operations.
"The professed medical premise for cultivating this marijuana is predominantly a ruse," Mims agreed. "Marijuana grown in these quantities is largely intended for distribution and sales, often to out-of-state destinations."
Follow Michael Doyle on Twitter
ON THE WEB
MORE FROM MCCLATCHY: