Almost 60,000 hectares of land formerly used as a cattle station has been added into the national parks estate as part of the new Mutawintji State Conservation Area.
The Mutawintji Board of Management, in partnership with the government, bought the 57,000-hectare Nuntherungie Station in 2015.
That land - 130km north-east of Broken Hill in the state’s far west - was on Thursday declared a state conservation area and will be absorbed into the pre-existing 69,000-hectare Mutawintji National Park.
It will jointly be managed by the NSW National Parks Wildlife Service and Mutawintji Board of Management.
"The recognition of our land management practices and the benefits of 60,000 years of accumulated knowledge is exemplified by the expansion of our Country under joint management," Mutawintji Board of Management chairperson Warlpa Thompson said.
The national park was handed back to Traditional Owners in 1998.
The area is home to the endangered yellow-footed rock wallaby and supports almost 30 other threatened species, including the eastern fat-tailed gecko, grey falcon and the black-breasted buzzard.
Matt Kean, the NSW environment minister, said the expansion “finishes a journey” that began in 1983 when the park was blockaded to protect Mutawintji rock art.
"By reserving Nuntherungie and adding it to the existing Mutawintji Lands we are expanding an exceptionally significant Aboriginal landscape and facilitating the continuing physical and spiritual connection to country for the Traditional Owners," he said.