Firefighters are battling a wildfire near Winters in Yolo County on Monday.
The Putah Fire, named after nearby Putah Creek, is burning off Highway 128 west of Winters.
Cal Fire said crews were first dispatched to the scene shortly after 11:30 a.m.
Scene of the fire.
Cal Fire Sonoma-Lake-Napa Unit
About 40 acres have burned so far. Cal Fire said the flames are moving uphill through light, flashy fuels.
Exactly what started the fire is unclear.