Authorities in Northern California say a secret underground bunker reached by a 100 foot tunnel was uncovered at a home in the small city of Anderson. Inside, officers report finding equipment for an illicit marijuana grow along with a large cache of illegal firearms and ammunition.
Michael Jay Kamfolt, 40, was arrested on January 20 on nearly a dozen weapons related charges after the California Highway Patrol carried out a search warrant at his property. Officers seized 13 firearms, body armor, high capacity magazines and about 10,000 rounds of ammunition, some of it armor piercing, according to the agency. One CHP leader said the discovery went far beyond an illegal grow and highlighted the threat to public safety.
Tip about an illegal grow sparks investigation
The case began in December 2025 when the California Highway Patrol Northern Division Canine Unit received a tip about a suspected illegal marijuana cultivation site in Anderson, about two hours north of Sacramento. After getting a search warrant, CHP Air Operations flew over the property to confirm what ground officers had been told.
Investigators then spent roughly a month watching and preparing before members of the Northern Division Warrant Service Team executed a search warrant on January 20. What they expected to be a marijuana raid quickly became something much more serious once they looked underground.
For people who see cannabis enforcement as a low level issue, that twist may be surprising. In practical terms, it shows how a tip about plants can sometimes uncover weapons that pose a wider risk to everyone nearby.
A 100 foot tunnel hides a concrete bunker
During the search, officers found an entrance that led into a roughly 100 foot long culvert sloping down from the property. At the end of that tunnel, they say, was a concealed underground bunker that could not be seen from the street.
The chamber was wired with electricity and ventilation, and it had a concrete floor with built in drainage and the supplies needed to grow marijuana inside a closed room. In simple terms, it was a hidden indoor farm tucked beneath the surface, far from daylight and curious eyes.
For most neighbors, an underground concrete room filled with lights and fans is not something they expect under a nearby yard. Who would imagine that a quiet property on a rural road could sit on top of a bunker instead of just soil and tree roots.
Illegal firearms, ammunition and body armor seized
Alongside the grow equipment, CHP says officers recovered 13 firearms, four soft body armor vests, 30 high capacity magazines and about 10,000 rounds of ammunition. The haul included a sawed off shotgun, three AR 15 style rifles, at least one gun with its serial number removed and two weapons reported stolen in 1978 and 2016.
Some of the ammunition was armor piercing, a type of round designed to punch through protective vests and other barriers, which is tightly restricted under California law. Large capacity magazines that can hold more than ten rounds and many assault style rifles are also generally banned for private owners in the state, so investigators treated the bunker as much more than a private collection.
Chief John Pinoli of the CHP Northern Division said the operation “went far beyond an illegal grow” and that the bunker and weapons showed a clear public safety threat. He also praised what he described as the tireless work of the officers who built the case and carried out the search.
Charges against the homeowner and what comes next
Kamfolt was booked into the Shasta County Jail on nearly a dozen counts related to weapons and ammunition, including possession of an assault rifle, manufacturing of an assault rifle, possession of a firearm with an altered serial number and manufacturing of a so called ghost gun. A ghost gun is a firearm built from unfinished parts or kits that lacks a serial number, which makes it hard for law enforcement to trace when it turns up at a crime scene.
California law treats ghost guns, unregistered assault style weapons and large capacity magazines as serious offenses because they sit outside the usual background check and registration systems. At the end of the day, that means these weapons can move through communities without the checks that apply when someone buys a gun at a licensed store.
According to Shasta County Jail records, Kamfolt was no longer in custody by the Tuesday after his arrest, and the investigation by CHP detectives remains active as they follow additional leads. For residents of Anderson, the case is a reminder that major crime scenes can unfold behind ordinary fences and that one anonymous tip can bring a secret bunker to light.
