Wild horses were first recorded in the area in 1876.

Kaimanawa wild horses are not a genetically unique population. They have roughly the same genetic makeup as domesticated horses, although they are of mixed breed with diverse genetic influences. They have most in common with the Thoroughbred and Station Hack breeds.

Prior to 1981 there was no official monitoring of horse numbers, movements or range, or any formal management. It was believed there were plenty of wild horses.

Land development, increased competition with human activities, and hunting drove down the number of wild horses. By 1980 they were limited to the southern Kaimanawa area where only about 174 wild horses remained.

New Zealanders were concerned these horses would be lost, so in 1981 a protected area for "horses known as the Kaimanawa Wild Horses" was established. But once protected, the horse population surged – threatening the area's fragile ecology and the horses themselves.

In consultation with all stakeholders, a plan was prepared. Horse numbers are now managed in accordance with the approved plan which includes operations such as annual counts, musters and rehoming of surplus horses.