UPDATE (7:04 p.m.) - Aerial resources have mapped the fire at more than 150 acres, according to the Ventura County Fire Department.
(5:37 p.m.) - Smoke from a brush fire in Ventura County was visible in southern Santa Barbara County on Monday afternoon.
The Casitas Fire broke out shortly after 4:30 p.m. near Lake Casitas.
According to the Ventura County Fire Department, it had burned about 30 acres by 5:30 p.m.
Crews were attacking the fire on the ground and in the air.
Fewer than ten homes in the area have been evacuated. Those under the evacuation order include the Santa Ana Creek and Cooper Canyon area north of Casitas Pass and Baldwin Road, west of Ranch Road.
Highway 150 was closed at the Ventura/Santa Barbara County line. Only local residents with proper identification are allowed through.