A massive California wildfire has prompted evacuation orders and a highway closure. The Madre Fire ignited Wednesday afternoon in San Luis Obispo County, according to Cal Fire. It has since grown to 79,936 acres and is 30% contained as of Sunday, fire officials said.

The fire sparked in the Los Padres National Forest in San Luis Obispo County and was growing exponentially, officials warned. The area is mostly uninhabited.

The blaze is burning in a rural area of San Luis Obispo County, in the central coast, but its smoke has spread to nearby counties.