Firefighters are responding to a 20-acre fire burning near Chesbro Reservoir, west of Morgan Hill.
The blaze, near Oak Glen Avenue, is threatening structures and has prompted evacuations in the areas of Rolling Hills Drive and Rocky Ridge Road, according to Cal Fire.
Morgan Hill police officers began evacuations in the Woodland Estates area about 3 p.m., according to the department's Facebook page.
No injuries have been reported.
No other information was immediately available.