The Bear Fire, which threatened hundreds of homes in Sierra County this week, continued to rage Wednesday night as firefighters battled sweltering late summer conditions in rugged terrain.

The fire had burned 3,000 acres as of Wednesday morning, 1,000 acres more than conditions around 6 p.m. Tuesday, according to the National Interagency Fire Center’s Northern California operations. The blaze, burning 5 miles south of Loyalton, remains at 0% containment, firefighters with the U.S. Forest Service and Cal Fire said.

Interagency Management Team 2, a group of federal, state and local firefighters called out to complex incidents, has been assigned to the fire, joining crews from the Tahoe National Forest and Cal Fire’s Nevada-Yuba-Placer unit.

Tahoe National Forest officials said Tuesday that a combination of warmer temperatures and strong winds were intensifying the fire as crews worked to set up containment lines. Temperatures in the area are expected to be just below 90 degrees on Wednesday with winds from the east between 5 and 10 mph.

Firefighters were still trying to gain access to some parts of the fire due to steep, rocky terrain and limited road access. Aircraft are being used to drop fire retardant and water.

As of Tuesday, 286 buildings and 536 residents were under evacuation orders, while 760 residents were without power. Sierra County officials issued a mandatory water restriction for area residents on Tuesday, suspending outdoor watering and asking residents to limit indoor use as much as possible while firefighters battle the blaze.

Evacuation orders and road closures remain in effect for residents in Sierra Brooks and in zones SIE-E030, SIE-E031, SIE-E032, SIE-E058, and SIE-E059. Road closures include Tahoe National Forest System Lands east of Highway 89 and north of County Road 450 at Henness Pass Road. The closure extends north along Highway 89 to the end of National Forest System Lands south of Sierraville.

The closure extends east and north along the forest boundary to the Antelope Valley State Wildlife Area and east to the junction with the Humboldt-Toiyabe National Forest.

The southbound closure continues along the Tahoe National Forest boundary to the intersection with the Truckee Ranger District, where the closure boundary continues west along County Road 860 until it becomes County Road 450 back to Little Truckee Summit.

The fire started Monday afternoon on the northeast side of the Tahoe National Forest, about 100 miles northeast of Sacramento. The cause of the fire is unknown and under investigation.