Garneill was named for Garnet Neill, the wife of a local area rancher. In 1903, the Central Montana Railroad station was established and was named Ubet in memory of the famous old stage station just a few miles to the west. At a later time, the railroad eventually changed the town's name to Garneill at the request of the locals. Near Garneill sits a 2.5 ton granite rock known as the Ubet and Central Montana Pioneers Monument. The concrete base in which this rock sits are pieces of embedded ore, petrified wood and Indian relics. In honor of the early pioneers, their names and dates of their arrival have been carved in it. The first post office was opened in 1899 with Edwin C. Hill as postmaster.
Garneill is located in central Montana, between Lewistown and Harlowton on U.S. Highway 191.