The NSW Rural Fire Service are controlling a bushfire about 20km south of Wyangala Dam, near Reids Flat.
Around midday on Tuesday, firefighters were "holding" the fire ahead of worsening conditions in the afternoon.
The blaze has burnt through about 180 hectares of bushland in steep, hard to access country.
The fire was alerted about 2pm on Monday, on Tarrants Gap Road north of Reids Flat.
The cause of the fire is still under investigation.
Two aircraft helicopters and two fixed-wing aircraft have responded. Approximately 60 firefighters and 20 fire trucks are working to contain the fire.
Two bulldozers, a grader and excavator continue to strengthen containment lines.
There's been no report of destroyed property and no people have been harmed.
"At the moment crews are holding the fire. The plan is to hold through worsening conditions this afternoon, and strengthening containment lines with heavy plant machinery and fire crews," district manager of the South West Slopes NSW Rural Fire Service Andrew Dillon said.
"We are well resourced in the air with two aircraft helicopters and two fixed-wing aircraft working. People in the area will have noticed quite a bit of aircraft activity.
"It's really difficult country. Steep, hard to access bushland."
Crews are expected to be controlling the fire for the next few days.
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