The annual cull of Kaimanawa horses will take place as soon as there is a weather window of two fine days.
The Department of Conservation says up to 150 horses will be rounded up this year by teams of musterers and a helicopter. This is 50 fewer horses than last year.
Wild horses are culled once a year from the Kaimanawa ranges to keep the herd number at the agreed size of about 300.
DoC says it expects fewer homes to be available this year because of the drought and the recession.
The muster could take place any time from now until early June.