Aussie Ark aims to create a 7000-hectare sanctuary for koalas in the Barrington Tops.
The not-for-profit organisation will use "exclusion fencing" for the $1.3 million project, which it aims to complete within three years.
The project, known as Koala Ark, aims to secure a wild population of 1000 to 1500 koalas.
Aussie Ark has dubbed the project the "world's first wild koala sanctuary".
The aim will be to protect the area from "intense bush fire", which can "decimate remaining populations within only days", as seen recently in NSW.
The project includes removal of introduced species such as horses, pigs, goats, cats, foxes and weeds.
Field officers will monitor the sanctuary over the long term.
Koala populations in parts of NSW and Queensland had experienced "catastrophic loss" and were heading for extinction by 2050 at the current rate of decline.
Aussie Ark president Tim Faulkner has started a Go Fund Me page, titled Saving the Koala, for the project.