GORMAN, Calif. — Authorities issued evacuation orders Saturday as a wildfire in Los Angeles County spread thousands of acres close to a major highway and threatened nearby structures, officials said.

The blaze that is being called the Post Fire burned more than 4,400 acres near the Interstate 5 freeway in Gorman, which is about 62 miles northwest of Los Angeles, according to the California Department of Forestry and Fire Protection, known as Cal Fire.

The flames broke out at around 1:45…