The underbrush is being removed with a combination of bulldozers and hand tools, as well as controlled burning operations, Captain Brandon Vaccaro, a spokesman for the Delta fire incident command, said. But the interstate was expected to open Sunday.
Pimlott said in the letter Thursday that additional funds would be used to hire more firefighters and secure additional helicopters for his agency.
The blaze in California's Shasta-Trinity National Forest was burning out of control after chewing through 36,970 acres of timber and brush since Wednesday.
The Carr fire has gone on to ravage 1000 homes and has killed at least seven people, while the Mendocino has been declared the largest in state history, having burnt through nearly 300,000 acres of land.More news: Novak Djokovic vs Juan Martin del Potro, US Open 2018 final
Latest numbers from the Shasta-Trinity National Forest show the fire has now burned approximately 22,000 acres of land and is still 0 percent contained.
"Multiple commercial vehicles and several structures have been damaged or destroyed" so far, according to the Northern California Geographic Center. East of Interstate 5 at Sims Flat, crews are using an existing Hirz Fire contingency line along Sweetbriar Ridge as an indirect control line for the Delta Fire to limit its northeastern spread.
The fire destroyed thousands of trees that could fall onto the highway.
The unrelenting flames have drained California's firefighting budget and prompted almost $1 billion in property claims even before the start of the unsafe fall fire season, officials said Thursday.More news: Rapper Mac Miller dead at 26
Others said over the scanner that the freeway was "littered with abandoned trucks" and that one of the burnt trucks was carrying timber. The truckers are exhausted and just want to get going. Evacuations have been issued for everything north of Vollmers/Delta to the Siskiyou County line.
Underhill didn't know how many homes were evacuated, since she said it's a rural area with scattered residences. A temporary flight restriction continues to be in effect over the fire area.
The fire has residents of nearby Dunsmuir on edge, amid heavy smoke, said Richard Dinjes, executive director of the city's chamber of commerce. The highway has been closed in both directions in that area.
A representative from the Shasta County Sheriff's Office could no immediately be reached for comment.More news: Turmoil at Tesla as executives leave and shares tumble