The New Zealand government strictly controls the population to protect the habitat in which they live, which includes several endangered species of plants.

There is also a small unmanaged population of feral horses on the Aupōuri Peninsula at the northern tip of the North Island.

The majority of Kaimanawa horses are small but tough and sure-footed, and they are widely popular as Pony Club mounts and showjumpers.

In the 1870s, McLean released a Comet stallion and several mares onto the Kaingaroa Plains and the bloodline mixed into the wild Kaimanawa Horse population.

In 1981, the Kaimanawa horse population, the size of the ranges, and the herd movements began to be officially measured.

There is also a small population of feral horses living on the Aupōuri Peninsula at the northern tip of the North Island.

For the Love of Horses is about their childhood and becoming New Zealand's best showjumping riders and the first time they tamed wild Kaimanawas, Stallion Challenges is about the year they tamed wild two Kaimanawa stallions each to compete in the Stallion Challenge competition, Mustang Ride is about the sisters taming wild mustangs in America to compete in the Mustang Makeover, Saving the Snowy Brumbies is about the sisters taming wild brumby horses from Australia, Ranger the Kaimanawa Stallion is told by a Kaimanawa stallion called Ranger who was tamed by the sisters, and the Showtym Adventures series is a junior fiction series about the sisters' favorite ponies from their childhood.

The Kaimanawa breed varies widely in general appearance, with heights ranging between 12.2 and 15 hands (50 and 60 inches, 127 and 152 cm) high.

They have a medium-sized head in good proportion to their body, with wide variation in shape due to the different conformation of their ancestors.

[7] Owing to the increase in population after protective legislation was put into place, the Department of Conservation developed a management plan for the Kaimanawa herd in 1989 and 1990.

Ecological objectives included ensuring that Kaimanawa horse does not adversely affect endangered, rare and biogeographically significant plants; ensuring that the herd does not further degrade the ecosystems in which it lives; and preventing the herd from spreading into the Kaimanawa Forest Park and the Tongariro National Park.

[4] The Department of Conservation has since 1993 carried out annual culls and muster of Kaimanawas to keep the herd population around a target level of 500 horses.

[4] The United Nations' Food and Agriculture Organization lists the Kaimanawa horses as a herd of special genetic value that can be compared with other groups of feral horses such as New Forest ponies, Assateague ponies, wild Mustangs, and with free-living zebras.

This lack of interaction may result in a herd with more wild and fewer domestic characteristics, which is of special interest to researchers.

Between 1994 and 1997, students from Massey University studied a population of around 400 Kaimanawa horses to learn their habits and herd dynamics.