(BCN) – Firefighters from Cal Fire responded to a vegetation fire on Saturday afternoon in unincorporated San Mateo County, east of Half Moon Bay, that had grown to two acres and significantly impacted traffic in the area.  Fire crews from Cal Fire's Santa Cruz-San Mateo Unit responded to the fire off Highway 92, otherwise known as San Mateo Road, near Quarry Road, west of state Highway 35, at about 3:35 p.m.  The fire has been labeled the Mateo Fire and was burning at a moderate rate of spread, according to Cal Fire. Air tankers from Cal Fire's Hollister Air Attack Base were called to assist.  Photo Courtesy: Cal Fire At about 4:45 p.m., the fire’s forward progress stopped. Cal Fire said several engines remained on the scene for several hours afterward to "mop up hotspots and make sure the fire is out." Heavy smoke was visible in the area, according to the San Mateo County Office of Public Safety Communications.  According to Cal Fire, traffic was significantly backed up on State Highway 92. Drivers were told to take alternate routes or to be prepared for delays.