Steve Largent places Henry Plummer in Fort Benton on Christmas Eve, 1863. The records of the Bannack Mining District are cited by Alva Noyes in his History of Southern Montana.

We also find that Power of Attorney was given by H. Plummer, to George Chrisman, to settle with parties who owed him $3,500.00, on half interest in No. 7 Dakota lode, on December 27th, 1863, recorded January 2nd, 1864— eight days before Plummer was hung. If Henry had been wise, he would have left Montana. As to this particular matter, I can find no final accounting with the Probate Court of Beaverhead, by Chrisman.

The hanging of Sheriff Henry Plummer has been told and retold many times and will not be repeated here. But why was he hanged? Was he the leader of an gang of road agents? There is no evidence for the existence of an organized gang. There were exactly two stage robberies during the entire 14 months Plummer was in Montana, and these had all the characteristics of spur of the moment incidents. They also netted negligible amounts of gold. There was one other attempted robbery of the Moody pack train carrying $75,000 in gold dust in early September. This was almost a comic affair, and ended up with the two inept robbers losing money and equipment rather than gaining. But there was violent crime, and two events, coming on the heels of the two stage robberies that fall, triggered the formation of the vigilantes.

In mid-December, a young German, Nicholas Tiebolt, was murdered near the ranch of George Ives, already known as a "rough," and suspected in the robbery of the Oliver stage—the second of the two that fall. Tiebolt's body was brought back for viewing in Virginia City, which aroused a good deal of outrage. Secondly, news arrived that Lloyd Magruder, a merchant who had made a good deal of money selling goods in Alder Gulch, was missing and feared dead on his way back to Lewiston over the Nez Perce trail. In response to the Tiebolt murder, a posse was formed to bring in the likely suspects. This was done, and resulted in the last trial before a miners court for a long time. George Ives was convicted and hanged. It was during and after the Ives trial that Wilbur Sanders undertook to swear in the first members of the Vigilance Committee, a secret society patterned closely on the San Francisco Committee of 1856.

Why didn't Henry Plummer take part in the Ives trial? The defense lawyers sent a message over to Bannack by way of Club Foot George, but there was no sign of the Sheriff. The chronology here is important. Henry Plummer had left Alder before the posse was formed to bring in George Ives, according to the Largent narrative, and had left Bannack for Fort Benton by the time the trial of Ives started. Thus he played no role in the Ives case, and likely did not hear of it until his return.

He did not know of the formation of the Vigilance Committee, since the members were sworn to secrecy, and, until they had hanged their first victims, Red Yeager and George Brown on January 4, 1864, there was no sign of activity. Even then, the news of bodies swinging on ropes at Laurin may not have reached Bannack for several days. He certainly did not suspect that the posse and/or vigilante activity was directed against him. After all he was a wholly respected member of the elite of Bannack. He boarded with the Vails, who were next door neighbors to the Sanders, and, he thought, he was on friendly terms with both the Sanders and the Edgertons—having entertained both families at a lavish Thanksgiving dinner at the Vails in November.

Even as a group of men came to Martha Vails to pick him up, he believed they wanted him to take custody of John Wagner, who was accused of attempted robbery of the Moody pack train. When he rose from the couch at Martha's where he was resting—he was ill, likely from his trip to Benton and back—he did not bother to buckle on his pistol, something rare for him. But, when the group hesitated, and he approached Wilbur Sanders next door, he was greeted with a military order from Colonel Sanders, "Company! forward march!" A short time later Henry Plummer was dead.

This ends the story of Henry Plummer in Montana. What's left is the question of why Henry Plummer was included in the list of vigilante victims. The vigilantes very likely executed some men guilty of crimes in what is now Montana. But Henry Plummer was innocent. Why was he included? The answer would have to come from Edgerton and Sanders, and they can no longer be deposed as witnesses.