A 83-year-old Parowan man has been charged after the 71,000-acre Brian Head Fire uncovered his explosive-filled doomsday bunkers, hidden for more than 30 years on public land in Iron County.

Firefighters found Richard O. Batt’s alleged cache of explosives, makeshift cabins and bunkers June 27, 2017 — 10 days after the fire began — when they heard “popping sounds” they soon realized were explosions, according to the Iron County Sheriff’s Office.

Crews hiked over to the site near Henderson and found modified grenades, explosive powder, fuses and ammunition.

(Courtesy of Iron County Sheriff’s Office) The remains of an explosive-filled bunker found during the Brian Head fire in summer 2017.

The discovery led authorities to remove ground crews from fighting the fire and allow only aerial attacks.

When authorities announced the finding that November, they said Batt was cooperative with their investigation and reportedly told investigators he’d been maintaining the structures for several decades and that the explosives weren’t hazardous.

Batt was charged Wednesday with a third-degree felony county of recklessness involving incendiary device parts. He scheduled to appear in Utah’s Fifth District Court on Sept. 11, according to court records.