A brush fire that broke out near Fort Tejon State Historic Park has grown to 720 acres and was 85 percent contained as of Saturday evening.

Kern County firefighters said 26 structures had been threatened at one point, but evacuations have been lifted and all roads are open. Fire officials were asking all residents to proceed with caution while returning to their homes.

A total of 458 personnel were fighting the blaze, firefighters said. The fire started about noon Friday, possibly from a big rig on the side of southbound Interstate 5 just north of Fort Tejon Road, but the official cause has not been determined.

One injury was reported.