The History of a Bridle narrative, circa 1900

The author of the narrative titled, The History of a Bridle: A True Story and Confession of Road Agents and Horse Thieves in Montana, is unkown. The donor, Merrill G. Burlingame (1901-1994), was a professor of history at Montana State University and an avid collector of historical documents for his own research. He regularly donated some of this collected material to institutions such as the Museum of the Rockies, the Montana Historical Society, and Montana State University. Sometimes provenance information was included with the donation, but just as often not, as is the case with "The History of a Bridle" narrative. The original manuscript itself could be a transcription from another source, but the handwriting does not appear to be Burlingame's and there are no clues as to where such a source might have been consulted.

The Vigilance Committee of Alder Gulch was formed in late 1863 in response to lawlessness in the mining camps of Bannack and Virginia City, Idaho Territory (later Montana Territory). In early 1864, the Vigilantes captured, unofficially tried, and hanged at least 20 "road agents" or outlaws, most of whom were members of the Plummer gang, including the leader (and elected sheriff), Henry Plummer. Once the Montana Territory was formed in late 1864 and territorial law established, vigilante activities declined in the immediate area. However, a new gold discovery at Last Chance Gulch, Montana Territory (now Helena, Montana), in 1865 led to a new boomtown and increasing lawlessness. A Committee of Safety was formed in 1865 and the group executed at least 14 alleged criminals over the next five years. While most members of the vigilante groups remained anonymous, numerous prominent territorial pioneers were purported to, or later claimed, to have been members. The numerical symbol 3-7-77 has long been associated with the Vigilantes, though its meaning is unknown.