The Temagog cabin was reduced to rubble amid hopes from the Rural Fire Service there were few or no homes in the area.
The owner has lived in the wood and stone cabin for more than 40 years and is currently travelling overseas.
The fire has burnt through more than 22,000 hectares of the Willi Willi National Park and surrounding bushlands.
Local farmers have also been impacted by the blaze, with fence lines and some crops destroyed.
"Fences are pretty devastated, there's no feed, we desperately need some help with feed," farmer Rowena Tweedie told 9News.
The Rural Fire Service (RFS) has warned that the upcoming fire season will be extremely challenging.
"We're absolutely gearing up for a difficult and long fire season," RFS Commissioner Rob Rogers said while addressing the media.
"It's going to be the most challenging season since 2019/20."
