100-foot tunnel entrance leads CHP to hidden bunker, 10,000-round weapons cache

SHASTA COUNTY, Calif. - California Highway Patrol (CHP) officers investigating an illegal marijuana grow in Anderson, California, discovered a sophisticated underground bunker containing a massive arsenal of weapons and ammunition. 

What we know:

The investigation began in December 2025 after the CHP Northern Division Canine Unit received a tip regarding an illegal cannabis operation. 

Following an aerial overflight that confirmed the suspicious activity, a month-long investigation culminated in the execution of a search warrant on January 20, according to the CHP.

Officers located a 100-foot-long culvert that served as the entrance to a fortified underground bunker. 

The subterranean space was fully operational with power, ventilation, drainage, and concrete floors, housing supplies used for large-scale marijuana cultivation.

Inside the bunker, officers recovered a staggering array of high-grade weapons:

• Three AR-15 style assault rifles (one with an obliterated serial number).
• A sawed-off shotgun and a machine gun.
• Firearms reported stolen as far back as 1978.

Michael Jay Kamfolt, 40, was arrested at the scene. 

What they're saying:

CHP Northern Division Chief John Pinoli emphasized the gravity of the find.

"This operation went far beyond an illegal grow. The combination of a hidden bunker and an alarming cache of illegal firearms and ammunition highlights the threat posed to public safety. I am proud of the tireless work of our Northern Division personnel that led to this arrest," he said.

What's next:

Kamfolt faces a litany of charges including manufacturing and possession of short-barreled rifles, machine guns, and "ghost guns." 

Detectives are currently tracing the 10,000 rounds of ammunition and the stolen firearms to determine if they are linked to other open criminal cases in Northern California.

The Shasta County District Attorney's Office is expected to review the case for formal prosecution.