The fire broke out near Old Conejo Road in the afternoon and had consumed at least 15 acres by 11 p.m. Fire officials estimated it was 75 percent contained at that point.
The smoke could be seen from a nearby residential area. The worst of the flames were burning along a ridge. The mobile home park is at the bottom of the hill.
No evacuations were ordered.
At one point, the southbound lanes of the 101 Freeway had to be closed. All lanes were re-opened.