Sgt. Chris Bertoli said narcotics task force agents conducted aerial surveillance on an area five miles up Geysers Road in the Healdsburg area and observed four large grow sites concealed in the brush.

The narcotics agents also noticed four campsites hidden in the thick vegetation, Bertoli said.

Because of the potential for confrontation with growers, a SWAT team accompanied narcotics agents and entered the gardens on foot at daybreak Friday, Bertoli said. The campsites were empty but the narcotics agents found stockpiles of fresh food, clothing, fertilizer and .22 caliber ammunition, Bertoli said.

Deputies and narcotics agents eradicated the marijuana plants, which were between 8 and 10 inches tall, Bertoli said.