Up to 300 Kaimanawa wild horses may need to be removed from the Waiouru Military Training Area during the muster this April.
Homes will be found for as many of these horses as possible, but any that are not adopted will be destroyed.
The muster is held every two years by the Department of Conservation to manage the herd at a sustainable level of 300 horses within the military area.
This number allowed for horses in the herd to maintain best condition and protected the fragile ecosystems unique to the Moawhango Ecological zone.
DOC operations manager Dave Lumley said rehoming as many horses as possible was an important part of a successful muster.