The San Bernardino County Sheriff's Department said that evacuation orders east of the freeway were lifted, which included East Oak Hills and South Hesperia, as well as for the West Oak Hills area.
Firefighters also brought containment up to 22 percent by the evening, although the fire has charred 35,969 acres.
A mandatory evacuation was ordered for all of Wrightwood, but officials said that only half of the community's 4,500 residents had complied.
Residents were also ordered to leave the areas of Lytle Creek Canyon, Lone Pine Canyon, Phelan and West Cajon Valley, where at least six homes were destroyed by flames.
MORE: Full list of evacuations, road closures, animal shelters and school information
Officials estimated that more than 34,000 homes and nearly 83,000 people were under evacuation orders. As of Thursday morning, authorities could not say how many homes were destroyed in the fire.
The American Red Cross said it has 301 people registered between its Fontana and Hesperia evacuation shelters. But they have room to grow should the fire threaten more communities.
At the San Bernardino County Fairgrounds in Victorville, horses, sheep, goats, pigs, cows and several llamas were sheltered from the fire. Owners who evacuated those animals are grateful for the safe haven, especially with an army of volunteers at hand.
"When you have an animal and it's depending on you to take care of it. This is worth every minute I don't get a minute of sleep," one volunteer said.
Bruce Kim, a resident of one of the evacuated communities, said his home is still standing after the fire initially blew through his area on Tuesday. Now he's picking up where firefighters left off by dousing hot spots after pumping water from his backyard pool.
But Robert Lyons was escorted from his home in the Cajon Valley off State Route 138. He said he had to get medicine from his home. The land around his area was scorched and outbuildings, garages and cars were burned as well.
Still, a majority of the homes, including Lyons', were saved.
Overnight Wednesday, crews made water drops on the fast-moving blaze in an effort to increase its containment.
About 1,580 firefighters from agencies throughout the region were on the scene, according to Travis Mason of the U.S. Forest Service.
They were supported by 178 engines, 17 water tenders, 17 helicopters and 12 air tankers, Mason said.
"I've been on the job nearly 25, 26 years. I've never seen fire like this," said Battalion Chief Mike Brown of the Los Angeles County Fire Department. "This fire is just that dangerous -- anything that's smoking, once it gets hot throughout the day -- has the potential to carry embers over to unburned fuel."
Efforts to contain the fire were taking place amid single-digit humidity and other conditions that Brown described as "very, very treacherous to fight in."
The blaze erupted Tuesday morning above Devore and, fueled by dry brush and fanned by gusty winds, it quickly spread across several thousand acres.
Gov. Jerry Brown subsequently issued a state of emergency for San Bernardino County.
The cause of the fire remains unknown.