There are now mandatory evacuations along Marsh Creek Road and Morgan Territory Road in Contra Costa County.
There have been four fires burning, with about 400 acres charred in total in the Round Valley Area.
Cal Fire said a Fire Warning on Morgan Territory Road had been issued due to the growing fire, which was sparked by lightning earlier Sunday.
Multiple fires caused by lightning that broke out across the county are being called the Deer Complex.
The fires are south of Briones Valley Road in Brentwood, at Marsh Creek and Deer Valley roads, and inside Round Valley Regional Park.