A controlled burn is causing smoke to be visible in a portion of northern San Luis Obispo County.
CAL FIRE SLO crews began working Monday to burn about 944 acres of private ranch land on the west side of Huer Huero Creek about four miles south of Creston.
The burn is designed to reduce the fire risk to the Atascadero, Santa Margarita and Parkhill areas.
CAL FIRE says the area is within the footprint of the 1989 Chispa Fire, which the seventh largest wildfire recorded in San Luis Obispo County.
Helicopters, a bulldozer, hand crews and engines are all being used during the prescribed burn, which is expected to continue through Wednesday.
About 161 acres were burned Monday and another 350 were planned for Tuesday.