A herd of American bison is back in the wild in Sonora after more than two centuries without a presence there. The animals are part of a restoration project in Cuenca Los Ojos, near Agua Prieta, where federal and state officials reviewed work on habitat corridors, grasslands, river areas, and wildlife protection. The project is still in its early stages, but the birth of new calves gives conservation teams a first measure of whether the herd can adapt.
Bison return to Sonora as restoration work expands
American bison have returned to Sonora as part of a broader effort to restore grassland ecosystems in the state’s northern border region.
Environment Secretary Alicia Bárcena visited Cuenca Los Ojos on May 15 and 16 with Sonora Gov. Alfonso Durazo, officials from national protected areas, and conservation staff. The visit focused on the species’ reintroduction and the work needed to protect the surrounding habitat.
The project began in February 2026, when 29 bison were moved from the Janos Biosphere Reserve in Chihuahua to Rancho Los Ojos Calientes, in Sonora. The group included 10 males and 19 females.
Several of the females were already pregnant when they arrived. Since then, 10 calves have been born in the new population.
A project tied to grasslands, water and wildlife movement
The bison project is not being handled as a stand-alone animal release. Authorities reviewed biological corridors, habitat connection work, river restoration, grassland recovery, and infrastructure meant to help wildlife move and remain protected.
The work also includes population management, health monitoring, gradual territorial expansion, and regulatory measures. The stated goal is to give the species a long-term chance to remain in its historic habitat.
Bison play a role in grassland recovery. Their movement and grazing can help native vegetation, soil structure, and seed dispersal. In northern Mexico, those functions are part of wider restoration work in damaged grassland areas.
Sonora joins a wider recovery effort in northern Mexico
The Sonora project builds on earlier work in Janos, Chihuahua, where bison conservation has been underway for years. Janos is known for protecting some of the last natural grasslands in northern Mexico, and includes the bison among its representative species.
For residents in Mexico, the story is also a reminder that conservation work often depends on long timelines. The Sonora herd was moved only months ago. The births are an early result, but the project will depend on continued monitoring and habitat protection.
The next test will be whether the herd remains healthy, reproduces over time, and can live within restored grassland corridors without losing the conditions that made the reintroduction possible.
