More than 4,000 marijuana plants were seized Thursday morning in the Cleveland National Forest, San Diego County sheriff's officials said.
Officers from federal agencies and SWAT and helicopter teams found the small farm tucked into the woods about 1 mile north of Palomar Observatory, said Sheriff's Lt. Pat Kerins.
Authorities found crude huts made of plastic sheeting where people tending to the farm apparently slept, said Kerins, a spokesman for the task force that investigated. There was also an elaborate drip irrigation system that carried water to the fields from a nearby stream.
Kerins said authorities discovered the farm's location from an unidentified tipster, who said it was protected by armed guards.