Catalina Island bison herd
The non-native but charismatic Catalina Island bison herd has existed for nearly a century.
This herd of American Bison roam and were supposedly first imported to California's Catalina Island in 1924 for the silent film version of Zane Grey's Western tale, The Vanishing American. However, the 1925 version of "The Vanishing American" does not contain any bison whatsoever and shows no terrain that even remotely resembles Catalina, according to Jim Watson, columnist for the Catalina Islander newspaper.
Over the decades, the bison herd grew to as many as 600 individuals. The population currently numbers approximately 150. Biologists found that the American Bison of Santa Catalina Island are not pure bred; 45 percent have a domesticated cow as an ancestor.
The island's bison herd is maintained and monitored by the Catalina Island Conservancy. Although the bison are not native to the island, they play an important role in the cultural fabric of Catalina. Therefore, the Conservancy has no plans to remove all the animals from the island.
Controlling the bison population, however, remains important for Catalina's overall ecological health. In the past, bison were routinely removed and sent to the mainland to auction. In 2004, the Conservancy partnered with the Morongo Band of Mission Indians, the Tongva (thought to be Catalina's original inhabitants some 7,000 years ago), and the Lakota tribe on the Rosebud Reservation in South Dakota. A hundred bison were relocated "home" to the Great Plains. Recently however, another solution was implemented. The Conservancy initiated a scientific study that determined that a herd of between 150 and 200 would be good for the bison, and ecologically sound for the island. Beginning in 2009, the herd was given animal birth control to maintain the population at around 150 animals.
On Wednesday, August 26, 2015, a contract worker from American Conservation Experience was injured by a bison while working near Tower Peak on Catalina Island.
On Saturday, February 17, 2018, a man camping at the Little Harbor Campground was gored by a bison. 
- Vogel, AB; Tenggardjaja, K; Edmands, S; Halbert, ND; Derr, JN; Hedgecock, D. "Detection of mitochondrial DNA from domestic cattle in bison on Santa Catalina Island". Anim Genet. 38: 410–2. doi:10.1111/j.1365-2052.2007.01614.x. PMID 17573784.
- Louis Sahagun (2009-11-20). "Catalina bison going on birth control". L.A. Times. Retrieved 2009-11-20.
- Ruben Vives (2015-08-26). "Bison gores Worker on Catalina Island". L.A. Times. Retrieved 2015-08-26.