Detwiler Fire engulfs nearly 80,000 acres

An aerial view of the Mariposa area as the Detwiler Fire split in two directions last week, threatening both Coulterville to the north and the main town of Mariposa to the south near its origins east of Lake McClure.
An aerial view of the Mariposa area as the Detwiler Fire split in two directions last week, threatening both Coulterville to the north and the main town of Mariposa to the south near its origins east of Lake McClure. Submitted photo

Nearly 80,000 acres were burned. More than 60 homes were destroyed. And some 5,000 people fled from their homes last week as one of the largest wildfires in the state spread its fury across Mariposa County.

The Detwiler Fire, sparked July 16 east of Lake McClure, quickly became a state and federal emergency as it exploded to nearly 46,000 acres in less than three days.

Its path of destruction was swift. With a combination of dead trees and tall, dry brush, flames were seen making leaps of more than 25 feet as the inferno barreled some 10-plus miles southeast, directly towards the town of Mariposa. Around noon on July 18, the small community, home to about 2,200 people per the latest U.S. Census, was sent scrambling for shelter as mandatory evacuation orders were put into effect.

Hundreds of people found refuge in centers from Oakhurst to Sonora throughout the week.

As the blaze rushed across wildland only a few miles away from downtown Mariposa, firefighters, sheriffs, and assisting agencies requested every available asset to answer the call and save the historic town. Dozens of air drops and numerous strike teams were requested as flames crested a ridge a short distance from Mariposa County Jail to the northwest end of the town.

As day turned to night, with the flames approaching and only a single helicopter equipped with nighttime gear available for air support, firefighters made what some called a heroic stand as they built bulldozer lines and moved in for ground attack. At that point, Jeff LaRusso, a public information officer for Cal Fire, said hard work, and “a little bit of luck,” helped save the town.

“Early on, we had numerous times this fire changed directions,” LaRusso said. “But that night, we got a shift in the wind that caused the fire to reverse directions. I think we got a little bit of an escape from that, thanks to some real aggressive firefighting and just a great job by the guys and girls out there on the lines.”

During that evening, more than 2,200 personnel were assigned to the blaze, alongside more than 200 engines and other equipment. But the fire wasn’t done, and by its end, more than 5,000 firefighters from across the West were called in to help slow down the inferno.

The next morning, firefighters found a rising challenge as the blaze pushed in two directions - northeast towards Coulterville, and southeast past Old Highway Road. With at least eight air tankers making drops on the southeastern end throughout the day, Cal Fire found the blaze making its hardest charge towards the north, forcing the evacuation of Coulterville, Greeley Hill, and surrounding areas.

Air attacks used so much fuel July 19, with protecting Mariposa as a top priority, that Deputy Incident Commander Dave Russell said the tanks at Castle Air Force Base in Atwater ran dry. Officials called the level of air strikes “almost unprecedented.”

The next day, the fire continued its onslaught as it grew from 48,000 acres to more than 70,000 - around 110 square miles - with only 10% contained. By that evening, the flames had turned 50 homes, and at least 50 other buildings including the Little Church in the Hills in Mount Bullion, to ash.

But as a positive sign, during a community meeting in Merced that night, Nancy Koerperich, Chief of Cal Fire’s Madera-Mariposa-Merced Unit, said firefighters were “turning the corner.”

“We do this because we live in communities like yours,” Battalion Chief Jeremy Rahn added at a similar meeting in Oakhurst. “We do it because we are your firefighters.”

Photos and videos were posted online of firefighters stopping to water gardens and perform other home upkeep in evacuated areas, when they got the chance.

On July 21, after days of being evacuated, the corner had been turned, at least in the main area of Mariposa. At 11 a.m., evacuation orders were lifted in downtown Mariposa and nearby homes, followed by additional areas being reopened later that night and over the next several days.

By Tuesday morning this week, it appeared the raging firestorm had finally tamed, as it remained at 78,900 acres from the previous day, and was 65% contained. The number of destroyed homes, 63, also remained the same, with 13 houses damaged. One commercial structure was lost to the flames, with 67 minor structures destroyed and eight damaged.

Most evacuation orders, except those around the Coulterville area, had also been lifted by Tuesday.

Smoke from the blaze impacted Yosemite National Park, the Mountain Area, and Valley as hazy skies reigned for much of the week. Health cautions were issued by the San Joaquin Valley Air Pollution Control District. Conditions appeared to clear up this week.

During the peak of the fire, Pacific Gas and Electric Company reported around 11,000 customers lost power. Throughout the entirety of the blaze, around 220 PG&E workers, as well as 190 contract workers, made 24-hour repairs to some 250 power poles downed by the flames, working out of the company’s base near Mariposa-Yosemite Airport. Electricity had been restored to all but some 170 customers as of Tuesday.

The Detwiler Fire’s expected containment date was Aug. 5, though officials said cleanup efforts would last well beyond that day.

The cause of the fire remains under investigation. As of Tuesday, the estimated cost to fight the blaze was $45.2 million, with a projected final cost of $60 million, Cal Fire Information Officer Jeff LaRusso said.