Authorities say the fire began as a controlled burn on Tuesday, but high winds sent the fire raging through a dry riverbed near Riverside Drive and Seneca Road.
Mandatory evacuations were lifted overnight, and people were allowed back into their homes between Victorville and Apple Valley.
San Bernardino County Fire spokeswoman Tracey Martinez says the permitted burn by the county regional parks agency was supposed to clear out cattails at Mojave Narrows Regional Park, but shifting winds blew it out of control.
PHOTOS: Brush fire burns near homes in Spring Valley Lake
About 200 firefighters are battling the blaze on the ground and from the air.
The San Bernardino County Fire Department says the fire is 30 percent contained. Flames destroyed a car and a shed, but no homes were damaged or destroyed.
The Associated Press contributed to this report.