Cal Fire declared the Calf Fire east of Santa Margarita 100 percent contained on Wednesday afternoon.
Described as a fast-moving wildland fire, it broke out on Monday afternoon and quickly burned 640 acres of grass, old-growth brush and oak woodlands in the Park Hill area, according to a Cal Fire press release. No structures were damaged.
Investigators determined that the fire was caused by equipment use. Cal Fire says that a landowner was clearing star thistle, an invasive weed, with a mower.
It was the first major fire in that area in 50 years, Cal Fire said.
San Luis Obispo County Fire Chief Robert Lewin said, this fire fight was successful thanks to the aggressive fast attack by firefighters, homeowners doing their part by creating defensible space around their homes, and a pre-attack plan developed by Cal Fire with funds from the Fire Safe Council.
At the height of the blaze, more than 900 firefighters were assigned to the fire. These firefighters came from many local, state and federal agencies, according to the press release.
The San Luis Obispo County Sheriffs Office, California Highway Patrol, the American Red Cross, and the Horse Emergency Evacuation Team were lauded for a quick evacuation of the area. Evacuation orders have been lifted and all roads were opened by Wednesday afternoon.
Fire crews will remain at the scene through the weekend to mop up hot spots.