The Madre Fire has grown to more than 52,500 acres in San Luis Obispo County.

At the outset of the blaze, the San Luis Obispo Sheriff's Office estimated that some 500 acres were already burned at the scene, near the 10000 block of Highway 166 in the Los Padres National Forest.

A minor, 3.3-magnitude earthquake struck in Northern California on Monday, according to the United States Geological Survey.

The Wolf fire in Riverside County is now more than 2,400 acres in size, although firefighters are making progress.