Ninety per cent of the Snowy Mountains brumbies would be culled over the next two decades, under a plan released by the NSW government.
The draft wild horse management plan for Kosciuszko National Park aims to cut the population of wild horses in the park from 6000 to about 3000 in the next five to 10 years.
The population would be dramatically slashed to just 600 within 20 years, confining the wild horses to three locations inside the national park.
Current numbers of wild horses are unsustainable and the untamed animals are damaging the park's fragile alpine and subalpine landscapes, NSW Environment Minister Mark Speakman says.
Releasing the controversial draft plan on Sunday, Mr Speakman acknowledged wild horse management was an "emotive and complex" issue.
"There are diverse opinions in the community and often deeply held views which polarise stakeholder groups," Mr Speakman said.
"It is clear, however, that the broader community values the unique environmental values of Kosciuszko National Park and looks to NPWS to protect these values."
Possible measures to slash the population include trapping, ground shooting, fertility control, rehoming and mustering.
Aerial shooting, brumby running and roping have been ruled out.
Feedback on the plan will be taken until July 6.
