Fighting the Marshes Fire near Moccasin cost about $2.5 million through Wednesday morning, according to Cal Fire estimates.

Earlier Wednesday, Cal Fire staff in San Andreas announced the 1,000-acre blaze was started shortly after noon Monday by a vehicle parked in dry grass about two miles up Marshes Flat Road, above Highway 49.

A Cal Fire investigation showed someone was driving a vehicle on Marshes Flat Road when they pulled over to take a break and parked in dry grass, where the vehicle ignited the grass. The driver moved the vehicle and tried to put the fire out, but failed. The driver’s name, age, gender and hometown were not released.

Greg Adams, Cal Fire’s Tuolumne-Calaveras Unit division chief of administration, said no one has been cited or charged for starting the Marshes Fire. Adams also said a Cal Fire investigation of how the fire started is still ongoing.

The fire was said to be 30 percent contained Wednesday afternoon. A total of 850 fire personnel remained assigned to the blaze. Equipment devoted to the fire included 79 engines, six tanker planes, six helicopters, 27 bulldozers and nine water trucks.

More than 65 agencies tapped

Since firefighting on the Marshes Fire began Monday, incident commanders called in equipment, crews and overhead personnel from 68 different agencies and aircraft from 21 different agencies.

Cooperators on the Marshes Fire include Cal Fire, the Tuolumne County Sheriff’s Office, the City and County of San Francisco, Hetchy Hetchy Water and Power, California Highway Patrol, Pacific Gas & Electric, the state Office of Emergency Services, the federal Bureau of Land Management and the U.S. Forest Service.

As of 10:30 a.m. Wednesday, the total cost of fighting the fire was about $2.5 million, Adams said.

Evacuations for more than a dozen homes in the Moccasin Ranch Estates subdivision were lifted Tuesday evening. Marshes Flat Road was reopened at Blanchard Road for residents only, and Tuolumne County Sheriff’s deputies and volunteers intended to maintain a road block. A closure on Highway 49 remained in place from Highway 120 to Blacks Creek Road at the Mariposa County line.

PG&E crews restored power to an unspecified number of customers who lost it due to the fire.

Although the fire prompted some temporary evacuations in the town of Moccasin, where the Hetch Hetchy Regional Water System maintains its Sierra headquarters, normal Hetch Hetchy water operations continued during the Marshes Fire.

There were no interruptions of water deliveries and no impacts to water quality from the Hetch Hetchy Regional Water System during the fire, City and County of San Francisco spokesman Charles Sheehan said. Normal hydroelectric power generation and deliveries also continued without interruption.

Afternoon heat

Wednesday afternoon temperatures in the area of the fire peaked in the low to mid-90s, according to the National Weather Service. The burn area is on a steep mountainside, and parts of the fire are difficult to access.

One firefighter was injured, Cal Fire staff in San Andreas said Tuesday. The firefighter was airlifted to a hospital in Modesto. Further details were not released.

As of Wednesday afternoon, a target date for full containment had not been announced.

Previous fires in the Moccasin area include the July 2006 Pedro Fire, which burned 1,998 acres, prompted the response of more than 1,100 personnel, and cost $3 million to contain in four days, according to Cal Fire.

The Pedro Fire burned near Don Pedro Reservoir, Highway 49 and the Moccasin Powerhouse. Investigators determined the Pedro Fire was human-caused.

Tip: ‘Don’t park hot vehicles in dry grass’

Cal Fire officials in San Andreas released a reminder Wednesday when they announced the cause of the fire was a vehicle parked in dry grass.

“Cal Fire would like to remind the public when traveling through areas of dry vegetation to be cautious where they park their vehicle,” staff with the state agency said. “Given the current conditions throughout California, you should only park your vehicle in an area cleared of vegetation.

“Parking your vehicle in grass, or driving through grass, can allow hot vehicle components, primarily the exhaust system and catalytic converter, to come in contact with the dry vegetation. These hot components are ignition sources that can cause a wildland fire.”

The vast majority of fires in California, 95 percent, are caused by people, according to Cal Fire.

Cooling trend

Forecasters with the National Weather Service in Sacramento say cold low pressure from the Gulf of Alaska will bring cooler temperatures and chances of rain for the Mother Lode and snow for the high country by Sunday.

Gusting winds are expected to develop in parts of the Central Sierra ahead of the weather system Thursday and Friday afternoon. Winds may increase the threat of fire starts, while increasing relative humidity levels may counter fire threats to an extent.

Winds in some mountain areas may gust up to 30 miles per hour Thursday afternoon and up to 40 mph Friday afternoon.

Daytime highs for San Andreas, Angels Camp and Sonora are expected in the 80s today, the 70s on Friday, the high 60s on Saturday and the low 60s on Sunday. Compared to Monday, Tuesday and Wednesday this week, it could be as much as 30 degrees cooler by Sunday.

Rain showers, isolated thunderstorms and snow at higher elevations are possible Sunday, with precipitation chances continuing into Monday. Snow levels may drop low enough to dust some Sierra passes with a few inches.