Fire crews both in the air and on the ground are making progress, but to contain this fire and prevent it from doubling back on the town of Idyllwild will take time.
Firefighters are concerned about the community of Pine Cove. They're telling residents there to be ready to go if the winds shift.
"We are expected some thunderstorms to come into the area this weekend, and the possibility of that happening, it could produce some downdraft winds, causing erratic fire behavior," said Chris Gaulding with the U.S. Forest Service.
Officials are also concerned about the column of smoke from the Mountain Fire, saying it could produce dry lightning. Officials are dealing with a changing and unpredictable fire.
"Fire sometimes creates its own fire weather, and today, our major concern is that the column of smoke is going to rise to about 30,000 feet in the air. If that happens, it's very possible that we would get lightning from our own fire smoke," said Tina Rose of Cal Fire.
Dry lightning plus dry vegetation could equal more fires, which is a major concern for crews and residents who decided to take their chances and stay behind.
"This morning, we have big chunks of burnt pine bark falling in our yard and piles of ash," said Robert Muir of Idyllwild.
Muir and his family chose not to evacuate, but they are watching the ridge closely and say they are packed and ready to go at a moment's notice.
Thousands of residents in Idyllwild and other nearby communities have been evacuated. Flames reached within two miles of the Palm Springs city limits on Thursday. The aerial fight continued overnight, which is something that hasn't happened in Southern California since the 1980s.
"Usually it cools down at night and we get more humidity. That hasn't happened," Rose said. "It's been burning like it's daytime for 72 hours in a row."
The fire started Monday in Mountain Center near the 243 and 74 highways. More than 4,100 homes are threatened by the fire, and an estimated 6,000 people have already left the area. Yellow tags mark which homes and businesses were evacuated.
Authorities say the wildfire was "human-caused," but it was unclear whether it was accidental or intentional.
Twenty-three structures have been destroyed, including seven homes. Fire officials said three mobile homes and three other residences were destroyed in Bonita Vista. In Pine Springs, one commercial building, a workshop, garage and cabin were destroyed. Eleven outbuildings and several vehicles also were destroyed.
More than 3,400 fire personnel are battling the wildfire. The cost of the firefighting efforts is estimated at $10.9 million.
Mandatory evacuation orders are in effect for residents in Idyllwild, Fern Valley and Trail Ends, the Andreas Canyon Club, south of Palm Canyon Drive in Palm Springs, Pine Springs and the Zen Mountain Center off of Apple Canyon Road. A voluntary evacuation order was issued for Pine Cove, where 700 homes are threatened.
Camp Ronald McDonald and Camp Joe Sherman have been voluntarily evacuated due to health concerns related to air quality.
Residents have been allowed to return to the Apple Canyon, Bonita Vista, Fobes Canyon and Spring Canyon Ranch areas because the fire threat to those areas have diminished.
Meantime, the Riverside County Office of Emergency Services on Friday put out an advisory for residents in the Pine Springs Ranch and Zen Center telling them to boil their water due to contamination from the Mountain Fire. Officials say the problem should be resolved in the next two to three days.
Evacuation centers for residents and animals have been set up:
-Hemet High School, located at 41701 East Stetson Avenue in Hemet
-Hamilton High School, located at 57430 Mitchell Road in Anza
-Beaumont High School, located at 39139 Cherry Valley Boulevard in Beaumont
-San Jacinto Animal Shelter, located at 581 South Grand Avenue in San Jacinto
-Beaumont Civic Center (small animals), located at 550 E. 6th Street in Beaumont
Evacuated residents are encouraged to check in with the Red Cross in Anza at Hamilton High School so the Red Cross can help them with any needs.
A hard closure remains in place on Highway 243 from the intersection of State Highway 74 to the Idyllwild Nature Center, south of Pine Cove.
The Pacific Crest Trail is closed from Highway 74 north to Saddle Junction. All of the trails connection to the Pacific Crest Trail are closed as well, including South Ridge Trail, Carumba Trail, Spitler Peak Trail, Fobes Trail and Cedar Springs. Hurkey Creek County Camground, and all of the hiking and mountain biking trails out of Hurkey creek and May Valley are closed.