As the Bear Fire continues to rage through the Tahoe National Forest in Sierra County, containment efforts have seen a slight uptick. According to the latest report from FOX5 Vegas, containment has grown to 23 percent. The fire, which has been burning since September 2, has now affected an area of 3,325 acres with over 900 personnel deployed to combat it.

Despite the increasing containment, the cause of the fire remains a mystery and is under active investigation. The mandatory evacuation order previously issued for Sierra Brooks residents has been downgraded to an evacuation warning, allowing for some affected by the fire to return to their homes, as reported on Thursday evening by CBS News. Forest officials have begun mop-up operations, focusing on extinguishing lingering hot spots and clearing hazardous materials from the fire's control lines.

"Today, we will focus on reinforcing the existing fire lines to minimize the fire’s impact on nearby communities and to increase containment," the U.S. Forest Service said in a statement obtained by FOX5 Vegas. They also noted that, weather permitting, aircraft would continue to aid the efforts by dropping water on the wildfire during daylight hours. The forecast, which includes minimal weather's impact for the moment, could change rapidly, so crews remain vigilant.

While some evacuees begin the cautious journey back to their residences in the Sierra Brooks neighborhood, where the downgrade to an evacuation warning was initiated at 4 p.m. Thursday, by the Sierra County Sheriff's Office says that the road closure at Smithneck and Highway 49 will only allow local residents with proper identification to pass. Residents are encouraged to stay aware as thunderstorms predicted to occur on Friday could offer a new set of challenges for the region already beleaguered by the conflagration.

With an area spanning east of State Highway 89 and north of Sierra County Road 450, the Bear Fire Closure Area restricts public access and aims to safeguard both the community and the teams fighting tirelessly against the flames. As the fire continues its unpredictable path, more than 280 structures have felt the shadow of danger, and the fire has directly impacted the lives of over 500 Sierra County inhabitants.

Updates on the situation, including evacuation zones and repopulation notices, are expected to continue as authorities and firefighters work to gain an upper hand on the Bear Fire. The cause of this wildfire, critical to understanding and possibly preventing future incidents, is still to be determined.