After the first two murders, the warning notes were rarely ignored. The lesson had been learned. The examples were plain. When Fred Powell's brother-in-law, Charlie Keane, moved into the dead man's home, the anonymous letter writer took no chances on Charlie taking up where Fred had left off and wasted no time on a first notice:

If you don't leave this country within 3 days, your life will be taken the same as Powell's was.

This was the message found tacked to the cabin door. Keane left, within three days.

All through Albany and Laramie counties, other men were doing the same. Houses of settlers who'd treated the company herds as a natural resource, free for the taking, were sitting empty, with weeds growing high in their yards. The small half-heartedly tended fields of men who'd spent more time rustling cattle than farming were lying fallow. No cow thief could count on a jury of his sympathetic peers to free him any longer. Jury, judge and executioner were riding the range in the form of a single unknown figure that could materialize anywhere, at any time, to dispense an ancient brand of justice the men of the new West had believed long outdated.

For three straight years, Tom Horn patrolled the southern Wyoming pastures, and how many men he killed after Lewis and Powell (if he killed Lewis and Powell) will never be known. It is possible, although highly doubtful, that he killed none at all but merely let his reputation work for him by privately claiming every unsolved murder in the state. It is also possible, but equally doubtful, that he actually shot down the hundreds of men with which his legend credits him.