The John Kinney Gang, also known as the Rio Grande Posse, were successful cattle rustlers and hired gunmen who primarily operated in Dona Ana County, New Mexico, in the early 1870s. John Kinney organized the gang, and in addition to cattle rustling, they also committed acts of robbery.
However, that changed In 1877 when they hired out to fight in the El Paso Salt War, a fight between El Paso businessmen over the salt deposits near the base of the Guadalupe Mountains. The next year, they made their guns available to the Dolan–Murphy faction in the Lincoln County War, which was a conflict between rival cattle barons.
Upon their arrival in Lincoln County, John Kinney was deputized by Sheriff George Peppin to counter Billy the Kid and his “Regulators.” With his gang acting as a posse, Kinney and his men were given the freedom to run rampant in the county. At the same time, former Kinney Gang member Jesse Evans and his gang were also were enlisted by the Murphy-Dolan faction.
Once the Lincoln County War was over, most gang members returned to Dona Ana County and their profitable cattle rustling activities. However, a few remained and joined up with another gang called Selman’s Scouts, and others joined the Jesse Evans Gang. The remaining members resumed their criminal activities in Dona Ana County until John Kinney was arrested in April 1883. Convicted of cattle rustling, Kinney spent the next three years in prison, and by the time he was released in 1886, his men had scattered.
After he was released, Kinney did not return to his former outlaw life but rather served in the US Army during the Spanish–American War and lived until 1919.