A range war is a type of usually violent conflict, most commonly in the 19th and early 20th century in the American West. The subject of these conflicts was control of " open range", or range land freely used for cattle grazing, which gave the conflict its name. Typically they were disputes over water rights or grazing rights and cattle ownership. 
Range wars occurred prior to the Taylor Grazing Act of 1934 which regulated grazing allotments on public land. Range wars included the Pleasant Valley War, Colfax County War, Castaic Range War, San Elizario Salt War, Mason County War, Barber–Mizell feud, Johnson County War and others.
Range wars have been the subject of movies and novels. Some examples are:
- Range War (1939) is a movie (featuring Hopalong Cassidy) about a group of ranchers in conflict with a railway company.
- The Virginian, a 1902 novel by Owen Wister, was based on the Johnson County Range War, presenting the case of the large ranchers and depicting the lynchings as frontier justice for cattle rustling. It was adapted four times as films.
- Shane is a 1953 movie (featuring Alan Ladd) that tells the story of a gunfighter taking the side of the farmers against cattlemen during a fictional range war loosely based on the Johnson County Range War.
- Open Range (2003), a film in which free-grazers take on a cattle baron who tries to use hired assassins to steal their herd.
- To The Last Man: A Story of the Pleasant Valley War, is a novel by Western author Zane Grey exploring the Pleasant Valley War in 1880s Arizona.
- Oklahoma! (1943 Broadway musical, 1955 film) Rodgers and Hammerstein musical about a cowboy in love with a farm girl, complicated by a rivalry between local farmers and ranchers over fences and water rights.
- El Dorado is a 1966 movie about an aging gunfighter who goes "straight" to help a lawman friend after being hired to intervene in a range war.
- Heaven's Gate (1980), is loosely based on the Johnson County War.
- "The Range War," a ballad by Todd Rundgren, focuses on a relationship between a boy whose "uncle runs cattle" and a girl whose "daddy runs sheep," and hints their relationship was opposed by both families, fueling this particular range war. 
- Chisum is a 1970 western movie loosely based on the 1878 Lincoln County War in New Mexico Territory, which erupted over mercantile economic competition rather than issues of range.
- Centennial features an episode titled 'The Shepherds' , which depicted a range war between cattlemen on one hand, against farmers and sheepherders on the other.
- A range war is referred to as the reason that cattle are being sold at low prices to a railroad in the twenty-third episode of Hell on Wheels.
- A range war was the subject of at least one episode of long-running old time radio show, Gunsmoke, called "Jaliscoe". 
- A range war was used as a plot in the 12th season of the TV show Dallas.[ episode needed]
- King of Texas is a 2002 American television movie transposing the plot of William Shakespeare's King Lear into the 19th-century American West.
- Man Without a Star, 1955, with Kirk Douglas.
While in previous centuries violence may have been involved,  the term is used for nonviolent competition for scarce resources, perhaps between ranchers and environmentalists,  or between ranchers and fans of wild horses. 
- Johnson, Marilynn S. Violence in the West: The Johnson County Range War and Ludlow Massacre: A Brief History with Documents. Bedford Series in History & Culture: First edition (September 18, 2008. p. 12. ISBN 978-0312445799
- For example, from the Santa Clarita Valley Historical Society site CECILIA RASMUSSEN. "Castaic Range War Left Up to 21 Dead". Santa Clarita Valley Historical Society. Retrieved 2004-07-04. (sourced from the Los Angeles Times): "The violent, long-running Jenkins-Chormicle feud, which started in 1890 over a boundary dispute, is a colorful and cruel saga — part fact, part myth — of barn burnings, ambushes and gun battles on horseback. It lasted more than two decades." describes a Southern California range war that started in 1890.
- For example, from the U of Idaho Range Management site Archived 2006-04-27 at the Wayback Machine. telling of conflict in Idaho: " Range wars continue, just as they did a century ago, between those who have grazing rights and those who do not. Today these range wars pit ranchers, with state grazing leases, against the environmental groups that are trying to restore the grazing lease areas to a healthy and pristine land. The weapons have changed from the cold steel of a gun to the amount of cold hard cash a rancher or an environmental group will pay for a piece of land."
- For example, from the MSNBC site, telling of Bureau of Land Management policy changes and impacts: "The mustangs' current troubles come thanks in part to another Western icon: cattle ranchers. There are currently 37,000 mustangs sharing public rangelands with several million head of cattle. The result has been overgrazing, exacerbated by six years of drought. To restore the land, the BLM has cut the number of cattle allowed, and ranchers say the horses and burros have to be pared substantially. "If we don't receive relief, and soon, we'll be out of business," Lemoille, Nev., rancher Kenneth Jones"
- For example, the Irregular Times site describes a disagreement among Democratic Party regulars in upstate New York as a "range war". In this case the "unfenced territory" is an election district, and the hearts and minds of Democratic party regulars
- For example, the Mac Observer site characterises the conflict between IBM and the SCO Group as a "range war". In this case, the "unfenced territory" is the Unix/ Linux marketplace, and the hearts and minds of technical, purchase influencing, IT people.