One killing after another occurred on the trails, and man after man was lost and never traced. Assaults were made upon many men who escaped, but no criminal could be located, and, indeed, there was no law by which any of them could be brought to book. The express riders were fired upon and robbed and the pack trains looted. No man expected to cross the mountain trails without meeting some of the robbers, and, when he did meet them, he expected to be killed if he made resistance, for they outnumbered the parties they attacked in nearly all instances. The outlaws were now indeed about three times as numerous as those not in sympathy with them.
Rendered desperate by this state of affairs, a few resolute citizens who wanted law and order found each other out at last and organized into a vigilance committee, remembering the success of the Vigilantes of California, whose work was still recent history. Plummer himself was among the first to join this embryonic vigilante movement, as was the case in so many other similar movements in other parts of the West, where the criminal joined the law-loving in order to find out what the latter intended to do. His address was such as to disarm completely all suspicion, and he had full knowledge of facts which enabled him to murder for vengeance as well as for gain.
After Oro Fino was worked out as a placer field, the prospectors located other grounds east of the Salmon River range, at Elk City and Florence, and soon Lewiston was forsaken, all the population trooping off over the mountains to the new fields. This broke up the vigilante movement in its infancy, and gave Plummer a longer lease of life for his plans. All those who had joined the vigilante movement were marked men. One after another they were murdered, none knew by whom, or why. Masked robbers were seen every day along the trails leading between one remote mining camp and another, but no one suspected Henry Plummer, who was serving well in his double rôle.
Meantime, additional placer grounds had been discovered a hundred and fifty miles south of Florence, on the Boise river, and some valuable strikes were also made far to the north, at the upper waters of the Beaverhead. All the towns to the westward were now abandoned, and the miners left Florence as madly as they had rushed to it from Oro Fino and Elk City. West Bannack and East Bannack were now all the cry. To these new points, as may be supposed, the organized band of robbers fled with the others. Plummer, who had tried Elk City, Deer Lodge, and other points, now appeared at Bannack.