The 45-mile (72-kilometer) stretch of highway near the state line with OR has been closed since a fire Wednesday turned hills both sides of the roadway into walls of flame.
It was near the site of the Carr Fire, which led to eight deaths and destroyed hundreds of homes in the city of Redding and nearby areas.
The interstate will be open to through travel with one lane in each direction for approximately 17 miles between Antlers Bridge in Lakehead and Flume Creek Road south of Dunsmuir.
"It's been ridiculously congested". The Snell Fire was only 10 percent contained.
"They had a lot of ground troops- they just didn't have many people to manage them, so our people were in charge of crews", he said. The general mood is just exhausted and upset. "And the locals just want a break from the wildfires".
Google Maps continues to update the California fire map with information about fires to which the California Department of Forestry and Fire Protection (CAL FIRE) is responding, along with information about evacuations and road closures.
A scorched logging truck sits on Interstate 5 as the Delta Fire burns in the Shasta-Trinity National Forest, California, on Wednesday, Sept. 5, 2018.
Firefighters aboard a special fire-fighting train joined the effort to contain the Delta Fire in Shasta County, California on September 7, spraying water on forests along the tracks near the Sacramento River.
Underhill said the same interagency team handling the Hirz Fire is taking over the firefight.
So what keeps the firefighters motivated?
"You can't underestimate the value of our people getting the opportunity to go over there and practice those skills on these large incidents and bring those skills home for us in the future".
The Delta Fire was human-caused, fire officials said, but they didn't indicate whether it was arson or accident.
Crews managed to remove the burned hulks and abandoned rigs on Thursday but flames continued to burn along the edge of the road in some areas, fire spokesman Brandon Vacarro said. It was only fully contained last week.
In Northern California, the Delta fire - which forced the closure of a stretch of Interstate 5, which runs the length of the state - had consumed almost 37,000 acres as of Saturday, the newspaper reported.