The bulk of the fire is threatening the Carrizo Plain National Monument, which is home to several endangered and threatened wildlife and plant species.

River 2 Fire initially started today at 4:46 a.m. in San Luis Obispo County, California. After being active for less than an hour, it has burned 0.5 acres of private land. There is no update on the containment of the fire and its cause remains unknown.

As of the Friday update at 9:15 a.m., the Madre Fire remained at 52,592 acres and was now 10% contained, according to Cal Fire. The blaze broke out near Highway 166 in the southeastern portion of San Luis Obispo County on Wednesday afternoon before quickly exploding in size as it raced across the grassy area.