Law enforcement agents collect physical evidence during an Aug. 6 raid on the biggest marijuana plantation ever found in Amador County. Photo by: Scott Thomas Anderson

They could hear rain falling through the trees. Crouched with their guns drawn, the SWAT members remained absolutely still until the helicopter roared overhead. Suddenly there was an explosion of movement and a running blur of camouflaged shadows as officers stormed a large marijuana plantation owned by the Mexican mob.

When the confusion died, law enforcement began seizing and destroying more than 23,000 marijuana plants which, combined with another 25,600 plants found later, equaled the largest plantation in Amador County's history.

They also began surveying a cluster of environmental damage left in the growers' wake.

The mission took place on Aug. 6 in a remote area above Pioneer. It was launched by the Amador County Combined Narcotics Enforcement Team, with ground support from the Amador County Sheriff's Office SWAT, El Dorado County Sheriff's SWAT and the U.S. Forest Service. Air support came from the Department of Justice's Campaign Against Marijuana Planting program, or CAMP.

As law enforcement swept through the woods into vast nurseries, one grower threw down a weapon as he and several others quickly fled into the thickest area of forest. They left behind acres of marijuana that were property of a drug cartel south of the border. Presently, at least four suspects are at large.

CAMP's Regional Operational Commander for Team 5, Ryan Pontecorvo, was dropped by helicopter into one of the nurseries. "They've been here for years," he remarked to Amador County Sheriff Martin Ryan, who was also present for the raid. "They have one of the most elaborate campsites I've ever come across."

Pontecorvo oversees CAMP operations in 12 counties and is credited with trying to stop the link between violent Mexican crime syndicates and their financial ties to marijuana production in California. "This was a highly sophisticated setup," Pontecorvo added. "It looks like they were here for the long haul."

Inspecting the growers' semi-permanent living quarters, officers found weapons, chemical fertilizers and roughly a year's supply of food. Various pieces of physical evidence confirmed that the growers worked for a drug cartel. Officers also began to calculate the plantation's devastating impact on the terrain, which was located near one of the most pristine areas of the Eldorado National Forest. Various sections of trees had been clear-cut. An entire section of the mountainside had been terraced away and riddled with makeshift watering systems. Thousands of plastic nursery cups were piled high in the vegetation. Closer to the encampment, which looks to have housed five people, the growers ripped gaping holes in the soil and filled them with trash, fertilizer and other toxic chemicals.

"They'll cut down trees and tear the woods up any way they want," said ACCNET agent John D'Agostini. "They don't care, as long as it creates a little daylight for their grow."

Ryan made his way down a hillside and discovered more clear-cutting. An outdoorsman, the sheriff was troubled at the sight of the fallen old growth.

"They did all of this just to get a few plants in this one spot here," Ryan observed. "And back at their dump site, we've got chemicals leaking into the groundwater."

The U.S. Forest Service will now look to deal with the extensive environmental damage that was uncovered by Thursday's raid.

More than 80 percent of marijuana plantations in California are found on public lands. According to ACCNET's Commander Jackie Long, almost all are controlled by Mexican drug cartels that also traffic methamphetamine, cocaine and heroin into the United States. Due to the extreme violence of these cartels - which has included the murder of Mexican law enforcement personnel, jury members, eyewitnesses and reporters - the White House has classified them as "terrorists."

The immediate danger to California citizens from the cartels has grown in the last decade. In 2000, a father and his 8-year-old son were both shot after stumbling onto a marijuana plantation in El Dorado County during a hunting trip. Though wounded, they survived the encounter. In February 2008, a Santa Rosa man was murdered by cartel growers after entering a plantation in the southern part of Lake County. June 2009 saw growers in Lassen County open fire on law enforcement, wounding two sheriff's deputies and leading to one grower being killed in the exchange.

"There have been plenty of shootings related to these operations now," Long said. "There's no doubt they can be violent."

Ryan was glad to have assistance from the state and El Dorado County in attacking the cartel's footprint on Amador. "I want to express my deep appreciation for the cooperation and support from all the agencies involved," the sheriff said Wednesday. "They helped us get this threat removed from our county."

The Ledger Dispatch had a reporter embedded with ACCNET during the Aug. 6 raid.