A vegetation fire broke out near the Sunol Regional Wilderness and grew to an estimated 108 acres until crews stopped its forward progress on Saturday afternoon.
The fire was first reported around 1:30 p.m. on Independence Day off Sheridan Road in an area with difficult terrain and a moderate-to-dangerous rate of speed, according to Cal Fire.
Between air and ground attacks, fire crews had reached 30% containment by 3:30 p.m. and had stopped its forward progress around 4 p.m., Cal Fire said.
Cal Fire reported the Sunol fire was 70% contained heading into Saturday night, with firefighters to remain on scene overnight mopping up the fire.
The Alameda County Fire Department was among the agencies to assist in the Sunol fire response. ACFD said it was one of 43 fires its crews battled for the Fourth of July.
Between 8 a.m. Saturday and 8 a.m. Sunday, ACFD reported seven structure fires, 22 vegetation or grass fires and 14 other fire incidents. It's unclear how many were connected to incidents of fireworks lit illegally for Independence Day.
ACFD responded to 175 other call incidents during that 24-hour period.