Is it lawful for citizens to slay robbers or murderers, when they catch them; or ought they to wait for policemen, where there are none, or put them in penitentiaries not yet erected?

On May 26, 1863, William Fairweather and a group of young men discovered gold in Alder Gulch, in the Ruby River valley, the U.S. state of Montana.

By late 1863 the remote gold fields and transportation links were rife with outlaws threatening and killing at will.

At the end of the year it was estimated that 102 travellers had been murdered.

As this became a more frequent occurrence locals began suspecting that these crimes were being carried out by a single group of outlaws, known as "road agents", under the control of Bannack sheriff Henry Plummer.

With law enforcement unable to cope or even actively joining the outlaw gang, citizens of this remote part of Montana took the law into their own hands and formed the Vigilance Committee.

Between January 4 and February 3, 1864, the vigilantes arrested and summarily executed at least 20 alleged members of Plummer's gang.

Thomas Dimsdale was there to witness it all.

Read here the gripping true account of popular justice in the Rocky Mountains.

His The Vigilantes of Montana first appeared as a series of articles in 1865 editions of the Montana Post, Virginia City's and Montana's first newspaper.

Thomas J. Dimsdale who died in 1866 was a member of the Alder Gulch Vigilance Committee and editor of the Montana Post. His early accounts of the Alder Gulch vigilante events are widely cited and the book version of his articles was published in Montana Territory in 1866.