A fire that broke out about 1 p.m. Thursday near Donnell Reservoir in Tuolumne County has spread to 300 acres and was burning northeast toward Alpine County as of about 6:30 p.m., according to U.S. Forest Service officials.

Diana Fredlund, spokeswoman for the U.S. Forest Service, said the blaze started in a rugged, remote area north of the Middle Fork Stanislaus River near the inlet to Donnell Reservoir in Summit Ranger District of the Stanislaus National Forest.

The fire was reportedly burning brush and timber, she said.

An evacuation advisory was issued by the Tuolumne County Sheriff’s Office about 6 p.m. for the areas of Wagner Track, Camp Liahona Clerk Fork and Clark’s Fork.

The Sheriff’s Office stated it will issue further orders if evacuation becomes needed.

Fredlund said a helicopter that was initially grounded due to smoky conditions was able to do bucket drops on the fire later in the afternoon.

Additional ground resources that were requested were expected to be in place by about 6 a.m. Friday because they had to be brought in from various areas due to the number of personnel working on other wildfires burning throughout the state, Fredlund said.

“Air support is definitely working, but I don’t know if there’s anybody physically fighting it right now,” she said. “There’s not a lot they can do and have to be careful because it’s remote terrain.”

Requested personnel included two Hot Shot crews, four hand crews, two strike teams that each include five fire engines, and two bulldozers.

“I’m not sure where they’re coming from, but I know they are on their way and will be in place as soon as they possibly can be because we want that fire taken care of, too,” Fredlund said.

Donnell Reservoir is the uppermost of three reservoirs owned and operated along the Stanislaus River as part of the of the Tri-Dam Project, a partnership between Oakdale Irrigation District and South San Joaquin Irrigation District.

The reservoir is also popular for day use, fishing and camping. It’s located about 10 miles northeast of Pinecrest Reservoir.

Contact Alex MacLean at amaclean@uniondemocrat.com or (209) 588-4530.