Wibaux County was created by the Montana Legislature in 1914 from parts of Dawson, Fallon, and Richland Counties.
The name comes from Pierre Wibaux, a late 19th-century cattle baron and friend of Theodore Roosevelt whose ranch was just over the border in Dakota Territory. According to legend, Pierre Wibaux’s cowboys surrounded the town of Mingusville, and wouldn’t let anyone enter or leave town unless they signed a petition changing the name of the town to Wibaux.
Upon his death, his ashes were spread over a hill west of Wibaux. Today, a statue of Pierre Wibaux stands on that hill. St Peter’s Catholic Church, in Wibaux is named after him.