From a Hollywood film production to a century on Catalina Island, the story of an unlikely herd and its uncertain future.
Why are there bison on Catalina Island? The story of Catalina Island bison history begins in 1924, when 14 American bison were brought to Santa Catalina Island for a Hollywood film production. The animals remained on the island and eventually established a herd that grew into the hundreds.
More than a century later, bison have become one of Catalina’s most recognizable animals. But their story is changing. Once a thriving, expanding herd, today’s bison are carefully managed, and recent conservation records describe a population of fewer than 80 animals that is no longer reproducing.
Their history connects Hollywood, island wildlife, conservation science, and the complex relationship between people and nature.
Why Are There Bison on Catalina Island?
Bison are not native to Santa Catalina Island. Their natural history belongs primarily to the grasslands and other habitats of mainland North America, far from this mountainous island off the Southern California coast.
Their presence on Catalina is the result of a Hollywood production from the silent-film era.
In December 1924, 14 American bison arrived on the island for a film project associated with adaptations of Western novels by Zane Grey.
The animals were never returned to the mainland.
What began as a temporary production arrangement became one of Catalina Island’s most unusual wildlife stories.
The Hollywood History: An Unexpected Arrival in 1924
The bison are famously associated with The Vanishing American, a 1925 silent Western.
There is, however, an interesting wrinkle in this familiar story.
Although the animals were brought to Catalina in connection with filmmaking, historians have not established that they actually appeared in The Vanishing American. They have also been linked to The Thundering Herd, another film project associated with the period, but the surviving evidence does not settle every detail.
What is clear is that the bison remained on Catalina.
The island offered open hillsides and areas of grassland where the animals could graze. With time, the original group became an established population.
In 1934, nine additional bison arrived, supplementing the island herd.
Hollywood may have provided the beginning, but the decades that followed turned these animals into a lasting part of Catalina’s landscape.
From Fourteen Bison to Hundreds
For much of the twentieth century, the Catalina Island bison population grew substantially.
Bison reproduced on the island, and additional animals were introduced during different periods. As the herd expanded, bison became a familiar sight in Catalina’s interior.
Historical population estimates eventually exceeded 500 animals.
That growth created challenges. Catalina Island has a finite amount of suitable habitat, and its native plant communities evolved without large herds of bison grazing across the landscape.
A large population of introduced herbivores can place pressure on vegetation and contribute to changes in sensitive island ecosystems.
The increasing herd therefore required active management, rather than being allowed to grow indefinitely.
The bison had become part of Catalina’s cultural identity, but they also presented a question that conservation managers continue to consider: how should a nonnative animal with a century of local history fit into efforts to protect the island’s native environment?
Life in Catalina Island’s Interior
Today, the sight of an American bison among Catalina’s hills remains striking.
These large mammals are predominantly grazers. They feed mainly on grasses and other available vegetation, moving through open areas and resting between periods of feeding.
Catalina’s seasonal landscape changes around them.
During wetter months, parts of the interior become green with fresh growth. In the dry season, hillsides take on golden and brown tones, and grazing conditions change with the availability of vegetation and water.
Bison can often appear remarkably calm while resting on the ground or standing among the grass.
Their size, heavy shoulders, thick coats, and distinctive silhouettes make them compelling photographic subjects.
An American bison rests in Catalina Island’s dry grass, with another animal visible in the background. Original photography by Island Moose.
The quieter moments are just as much a part of the herd’s story as photographs of bison walking across the landscape.
Managing the Catalina Island Bison Herd
As the herd expanded, the Catalina Island Conservancy and earlier managers used different approaches to reduce population pressure.
For years, bison were periodically gathered and transported off the island. Some were relocated to mainland destinations, including Native American reservations.
Beginning in 2009, managers introduced a different approach: an immunocontraceptive vaccine known as porcine zona pellucida, or PZP.
The objective was to control reproduction without relying solely on relocation.
The treatment was effective at reducing births. Published studies documented a sharp decline in annual calving rates during the early years of the program.
But the reduction in reproduction proved more persistent than initially hoped.
According to conservation records, the last calf was born in 2013. Managers subsequently withheld contraceptive treatments from breeding-age females, yet the herd did not resume producing calves.
This unexpected outcome has significantly shaped the modern story of Catalina’s bison.
How Many Bison Are on Catalina Island Today?
The Catalina Island Conservancy’s 2026 restoration documentation reports fewer than 80 bison remaining.
The same documentation states that the herd is no longer reproductively active.
That is a dramatic contrast with the historical population of more than 500 animals.
It is also important to distinguish the latest reported population from older visitor information. Some sources continue to describe management targets of approximately 150 bison or historical populations of 150–200.
Those figures should not be confused with the more recent count.
Because herd numbers can change, the most useful way to interpret the current situation is through dated reports rather than assuming an older published figure still represents today’s population.
Two American bison photographed against the hills of Santa Catalina Island. Original photography by Island Moose.
What Does the Future Hold for Catalina’s Bison?
The future of Catalina Island’s bison is uncertain.
With no recent reproduction reported, the existing population is gradually aging. Unless breeding resumes or management decisions change, the number of animals would be expected to decline over time.
The question extends beyond the herd itself.
Catalina Island is home to distinctive native ecosystems, including rare plants and wildlife found in few other places. Protecting and restoring those environments is central to the Catalina Island Conservancy’s work.
Bison, meanwhile, occupy a different place in island history from many other introduced animals.
They have become closely associated with Catalina’s Hollywood heritage, visitor experiences, and cultural identity.
The Conservancy has described bison as a managed part of the island landscape, while also pursuing broader habitat restoration initiatives.
That makes the herd a particularly interesting example of the challenges involved in island conservation: protecting native biodiversity while acknowledging more than a century of human history.
Whatever happens in the coming decades, the Catalina Island bison have already left a distinctive mark on the island’s story.
Photographing Catalina Island Bison
For a wildlife photographer, bison offer an unusual combination of scale, character, and landscape.
A resting bison can nearly disappear into dry grass, its rounded back and thick coat blending into the surrounding hillside. At other times, the animal’s powerful build and imposing shoulder hump stand out immediately against the open terrain.
Catalina’s changing light also transforms the scene.
Bright sun brings out the texture of their coats, while softer light can reveal subtle details in the fur, horns, and surrounding vegetation.
An American bison stands beside a tree on a dry Catalina Island hillside, with another animal partially visible behind it. Original photography by Island Moose.
Photographing bison responsibly means respecting their space.
Despite their sometimes peaceful appearance, bison are powerful wild animals capable of moving quickly and reacting unpredictably when approached.
A long lens and plenty of distance allow photographers to record natural behavior without disturbing the animals.
The most rewarding photographs often come from patience rather than proximity.
A Century-Long Wildlife Story
The story of Catalina Island’s bison began with 14 animals brought to a Hollywood filming location in 1924.
Over the following century, the herd grew, became part of the island’s identity, and eventually entered a period of intensive population management.
Today, the herd’s shrinking size adds a new chapter to that history.
Catalina’s bison are a reminder that the relationship between people, wildlife, and island ecosystems is rarely simple.
Their presence tells a story of filmmaking, adaptation, conservation, and change—all set against one of Southern California’s most distinctive landscapes.
Explore Catalina Island Bison Photography
These original wildlife photographs are part of the Island Moose collection, documenting bison in Catalina’s grasslands, hillsides, and natural surroundings.
Explore more portraits and scenes from the herd in the Catalina Island Bison Photography Gallery, where selected images are available as fine-art wildlife prints.
Research and further reading
- Catalina Island Conservancy — Restoration Project documentation (2026)
- Catalina Island Conservancy — Community Forum: Bison Health, Population and Management
- Smithsonian Magazine — The Uneasy Future of Catalina Island’s Wild Bison
- Journal of Mammalogy — Effects of Prolonged Immunocontraception on Bison
Population information reflects the latest dated Conservancy documentation reviewed in October 2026. Future herd-management decisions and population counts may change.