Numbats, bettongs, wallabies and phascogales have been released into protected conservation zones in the Pilliga National Park in the state's central north and the Mallee Cliffs National Park in southwest NSW in a bid to help them avoid extinction.
It's part of a plan to create 65,000 hectares of protected conservation areas in NSW national parks - "one of the most ambitious mammal rewilding programs in Australia" - according to Environment Minister James Griffin.
Some 150 animals have been released since August last year, joining a growing population of native animals in protected zones.
Foxes and feral cats have decimated populations of native wildlife, with cats estimated to kill 1.5 billion native animals around Australia yearly.
The conservation zones provide a safe haven for the native animals behind feral-proof fences where it's hoped their populations can rebound.
"We've seen the endangered bridled nailtail wallaby population double since it was reintroduced to this now feral-free area in August 2019, from 42 to about 90 at the latest estimate, including many females with joeys in pouches," Mr Griffin says.
The wallaby population is expected to grow to as much as 2000 in the Pilliga, Mr Griffin says, while 60 red-tailed phascogales, a tree-dwelling, mouse-like marsupial, are expected to grow to a 1500 strong population at Mallee Cliffs.
Five more feral-free zones are being established, to be managed in partnership between the National Parks and Wildlife Service, Australian Wildlife Conservancy and the UNSW Wild Deserts program.
Mr Griffin says the government hopes to remove up to 10 mammals from the locally extinct list within the next few years.
"Many of these and other species already reintroduced to these feral-free areas have not been seen in our national parks for more than a century," he says.