The Route Fire, which shut down parts of Interstate 5 in Castaic Saturday afternoon, was held at 462 acres, with firefighters able to achieve 63% containment by Monday morning.

Most of Interstate 5 was reopened Sunday, with only the northbound right lane of the freeway near Templin Highway remaining closed as of Monday morning, according to Caltrans.

The blaze began around 3 p.m. Saturday, quickly burning 50 acres in the first two hours and jumping Interstate 5, according to John Miller, a public information officer with the U.S. Forest Service, who led the firefighting efforts with assistance from Los Angeles County Fire Department personnel.

By Saturday evening, the fire had grown to 392 acres with 0% containment, however, firefighters were able to build containment lines overnight and through the day Sunday, according to Angeles National Forest officials.

While no structures were threatened, nor evacuations ordered, Interstate 5 was shut down in both directions Saturday, with right lanes in both directions remaining closed through the day Sunday as crews continued to monitor for hot spots, per Caltrans.

All southbound closures had been lifted Monday, with northbound closures expected to be lifted by Monday evening, according to ANF officials.

Two firefighters with burn injuries were transported for additional treatment Saturday in unknown condition, per ANF.

A double rotor helicopter makes a water drop on the ROUTE FIRE near the Golden State 5 Freeway and Templin Highway in Angeles Forest on Saturday, 091121. Dan Watson/The Signal

Firefighters set backfires to burn fuel in the path of the Route Fire that scorched over 300 acres north of Castaic Saturday. September 11, 2021. Bobby Block / The Signal.