Nate Champion knew too much.
For years, Champion and his small ranch had been a thorn in the side of the Wyoming Stock Growers’ Association, a cabal of the biggest ranchers in the Johnson County area.
The cattlemen insisted that Champion and his fellow small settlers were rustlers, constantly stealing cattle out of the bigger herds. Champion and the small grangers, on the other hand, insisted that it was the other way around; their small herds were constantly being rounded up and absorbed into the bigger operations. Rustling was done by a few bad actors on both sides, of course. But while the cattle barons could do their brand of rustling with impunity, the small ranchers had no real way to combat the accusations beyond sticking together.
This is where Nate Champion became important. He was a small man with a reputation as a fierce fighter, a man to be feared. Other small ranchers and homesteaders rallied around him, and the unified opposition was becoming a political and financial nightmare for the big ranchers. If Nate Champion went down, the big ranchers figured the small-timers would fold, rustling would cease, and they’d finally see some real economic progress (for themselves, of course; everyone else, not so much).
So Nate Champion had to be got rid of.
In November 1891, three men were sent out to his cabin to assassinate him. Two of them didn’t come back. And Champion, before going into hiding, told the sheriff and the local newspapers all about it. The cattle barons grew desperate. Their man was now in jail, and if Champion could testify against him, the trail could lead back to the businessmen who had ordered the hit. The cattlemen fully believed Nate Champion was a ringleader of rustlers, and to add insult to injury, his stubborn refusal to die had put them in legal jeopardy.
Now Nate Champion really had to be got rid of.
So the Stock Growers’ Association pooled its assets and decided to make sure that their word was law. They had always more or less owned Johnson County by means of money and influence; now they planned to own it for keeps.
Meanwhile, word reached them that Nate Champion had returned to his ranch. And the morning of April 9, 1892, the Johnson County Regulators — a force of 50 gunmen recruited from Texas and transported to Wyoming on a specially hired train — rode out to make him go away forever.
April 9. Me and Nick was getting breakfast when the attack took place. Two men here with us Bill Jones and another man. The old man went after water and did not come back. Nick started out and I told him to look out, that I thought there was someone at the stable and would not let him come back. Nick is shot but not dead yet. He is awful sick. I must go and wait on him.
It is now about two hours since the first shot. Nick is still alive; they are still shooting and are all around the house. Boys, there is bullets coming in like hail. Them fellows is in such shape I can’t get at them. They are shooting from the stable and river and back of the house. Nick is dead, he died about 9 o’clock. I see smoke down at the stable. I think they have fired it. I don’t think they intend to let me get away this time.
It is now about noon. There is someone at the stable yet; they are throwing a rope out the door and drawing it back. I guess it is to draw me out. I wish that duck would get out further so I could get a shot at him. Boys, I don’t know what they have done with them two fellows that staid here last night. Boys, I feel pretty lonesome just now. I wish there was someone here with me so we could watch all sides at once. They may fool around until I get a good shot before they leave.
Its about three o’clock now. There was a man in a buckboard and one on horseback just passed. They fired on them as they went by. I don’t know if they killed them or not. I seen lots of men come out on horses on the other side of the river and take after them. I shot at the men in the stable just now; don’t know if I got any or not. I must go and look out again.
It don’t look as if there is much show of my getting away. I see twelve or fifteen men. One looks like [name scratched out]. I don’t know whether it is or not. I hope they did not catch them fellows that ran over the bridge toward Smiths. They are shooting at the house now. If I had a pair of glasses I believe I would know some of those men. They are coming back I’ve got to look out.
Well, they have just got through shelling the house like hail. I heard them splitting wood. I guess they are going to fire the house tonight. I think I will make a break when night comes, if alive.
Shooting again. I think they will fire the house tonight.
It’s not night yet. The house is all fired. Goodbye, boys, if I never see you again.
Nate Champion made a break for it, a Colt revolver in one hand and his Winchester rifle in the other, but died in a hail of gunfire. He was shot 23 times. The Regulators left the note with his body…after they scratched out the name of the man he had recognized.
Some say he killed four of the attackers in the standoff; others say he only wounded three. Regardless, it was an epic last stand.
Champion’s death turned public opinion against the Cattle Association. The passers-by who had been fired on during his holdout escaped and warned people in the nearby town of Buffalo. When the Regulators rode from Champion’s KC Ranch to take over the town, they were rebuffed by a militia 200 strong. Local merchants had outfitted everyone who was able to hold a gun.
The Regulators had to hightail it for the TA Ranch, where they were besieged in the ranch house for days. The besieging force was just about to dynamite the house when federal troops showed up. That ended most of the violence, although hostility simmered for years afterward. 
By the time the Johnson County War burned itself out, it marked the end of the frontier era. The “wild west” had given way to the settled west.
 Chapel, Charles Edward. Guns of the Old West. Coward-McCann, New York, 1961. p 244-245.
 Nate Champion, Wikipedia; The Johnson County War: 1892 Invasion of Northern Wyoming, wyohistory.org.