According to news reports Wednesday morning, the 375-acre wildfire near Mount Diablo State Park is 80 percent contained.
Hundreds of firefighters responded to the wildfire charring ground near Mount Diablo State Park in a rural, unincorporated area of Contra Costa County.
Overnight low winds were helping to keep the fire from spreading rapidly, according to Cal Fire. The agency was fighting the fire with at least 23 fire engines and three bulldozers. Units deployed overhead — including one air attack, six air tankers and three helicopters — were released overnight due to darkness, but are expected to return today, Cal Fire said.
About 200 firefighters from Cal Fire, Contra Costa County Fire Protection District and San Ramon Valley Fire Protection District were responding. One firefighter was injured, spraining an ankle while battling the blaze.
A number of other agencies are assisting in the operations, including the California Highway Patrol and the Contra Costa Sheriff's Office, with a total of 250 personnel on the scene. Several structures were considered threatened by flames on Curry Canyon Road, according to Cal Fire, but no structures were burned.
Thick gray smoke was visible throughout the San Ramon Valley and eastern Alameda County, a witness said. Temperatures grazing 100 degrees and single-digit daytime humidity levels worked against firefighting efforts, according to Cal Fire, which did not have an estimate on when the fire would be fully contained. The cause of the fire is under investigation.
Bay City News contributed to this report.