Update: 4:00 p.m.
Firefighters are getting the upper hand on the fire, which has burned 50 acres.
Update: 3:00 p.m.
Ventura County firefighters are on the scene of what's being called a ten to fifteen acre brush fire in the eastern part of the county.
The Sage fire was discovered just after 2:30 Tuesday afternoon, in the hills above the Wood Ranch area of Simi Valley.
There are no reports of homes being threatened.
The blaze initially put up a huge plume of smoke visible for miles.
There is no word yet on the cause of the fire.