The fire had burned about 50 acres and was 55 percent contained at 6:30 p.m.
Northbound lanes of the Interstate 5 Freeway were closed due to smoke and fire in the area. Lanes were later opened, but one northbound lane was expected to remain closed until 3 p.m. Tuesday, according to the California Highway Patrol.
The closure was between Templin Highway and Vista Del Lago Road on the east side of the freeway. The fire was burning about halfway between Castaic Lake and Pyramid Lake.
The fire began near Paradise Ranch Road. The fire began when a tractor-trailer caught fire on the side of the freeway and spread to the surrounding brush.
A mobile home park was briefly threatened by flames but was not evacuated. A gun club nearby was evacuated as a precaution.
Winds were relatively mild.
City News Service contributed to this report.