Macarthur locals took to social media in droves after spotting several red figures walking through Campbelltown yesterday.
The hooded and cloaked figures are members of a worldwide performing activist art group known as the Red Rebel Brigade.
The Red Rebels visited Macarthur after contacting community campaigner Sue Gay about the plight of the region's koalas.
Mrs Gay said the activists wanted to raise awareness about the struggles faced by koalas due to development in the region.
"They were simply wanting to raise awareness about the environmental impacts of development on our koala population," she said.
"It was really peaceful - I wouldn't even call it a protest because it was more about just getting a message out there.
"It was more like a gathering because we don't need aggression or nastiness to get the message across."
The Red Rebels started at Campbelltown Station before catching a train to Macarthur Station and walking through the outdoor restaurant strip on Kellicar Lane.
The group then made its way to the new Koalatown sign at the intersection of Narellan and Blaxland roads.
Mrs Gay said the group was very conscious of social distancing and maintained Covid-safe practices including wearing masks.
She said the group was met with mostly positive response.
"We had people ask us what they were doing and they were very supportive when we told them," she said.
"We even had a train conductor ask how they could help.
"On social media people were more negative but in person people were generally a lot more positive.
"We were asked to leave Macarthur Square by security which was annoying."
Mrs Gay said Macarthur's koala population was an extremely important colony.
"They are chlamydia-free so they aren't at risk of the infertility that comes with that disease," she said.
"They are at risk of dog attacks too, but most of the injured koalas we see are traffic related.
"We have already lost a few koalas this season.
"We will keep fighting for the government to recognise that it is in the unique position of being able to prevent the extinction of koalas."
The NSW government recently unveiled a draft plan to protect critical biodiversity assets and an important koala population in the Campbelltown and Wollondilly area.
Environment Minister Matt Kean says the draft plan includes a new koala reserve to ensure Sydney's chlamydia-free koala population is protected.
"The Georges River Koala Reserve will protect up to 1885 hectares of existing koala habitat and enhance the connectivity of fragmented patches of important habitat, including protecting the important north-south koala corridor so this iconic species can move about safely," he said in a statement earlier this year.
The government is expected to spend $84 million in the first five years planting 100,000 trees in the reserve to restore koala habitat and to install 120 kilometres of koala fencing.
The draft plan spans eight local government areas including Blacktown, Fairfield, Liverpool, Campbelltown, Camden, Wollondilly, Hawkesbury and Penrith.