Westport was at that time, like all steamboat towns in the era of water navigation, the harbor of as great a lot of ruffians as ever escaped the gallows. There was especially a noted gang of land pirates, the members of which had long indulged in speculations regarding the probable wealth of the Mexican Don, and how much coin he generally carried with him. They knew that it must be considerable from the quantity of goods that always came by boat with him from St. Louis.

At last a devilish plot was arranged to get hold of the rich trader's money. Nine men were concerned in the robbery, nearly all of whom were residents of the vicinity of Westport; their leader was one John McDaniel, recently from Texas, from which government he claimed to hold a captain's commission, and one of their number was a doctor. It was evidently the intention of this band to join Warfield's party on the Arkansas, and engage in a general robbery of the freight caravans of the Santa Fe Trail belonging to the Mexicans; but they had determined that Chavez should be their first victim, and in order to learn when he intended to leave Santa Fe on his next trip east, they sent their spies out on the great highway.

They did not dare attempt their contemplated robbery, and murder if necessary, in the State of Missouri, for there were too many citizens of the border who would never have permitted such a thing to go unpunished; so they knew that their only chance was to effect it in the Indian country of Kansas, where there was little or no law.

Cow Creek, which debouches into the Arkansas at Hutchinson, where the Atchison, Topeka and Santa Fe Railroad crosses the historic little stream,[23] was, like Big and Little Coon creeks, a most dangerous point in the transcontinental passage of freight caravans and overland coaches, in the days of the commerce of the prairies. It was on this purling little prairie brook that McDaniel's band lay in wait for the arrival of the ill-fated Don Antonio, whose imposing equipage came along, intending to encamp on the bank, one of the usual stopping-places on the route.

The Don was taken a few miles south of the Trail, and his baggage rifled. All of his party were immediately murdered, but the wealthy owner of the caravan was spared for a few moments in order to make a confession of where his money was concealed, after which he was shot down in cold blood, and his body thrown into a ravine.

It appears, however, that the ruffians had not completed their bloody work so effectually as they thought; for one of the Mexican's teamsters escaped, and, making his way to Leavenworth, reported the crime, and was soon on his way back to the Trail, guiding a detachment of United States troops in pursuit of the murderers.

John Hobbs, scout, trapper, and veteran plainsman, happened to be hunting buffalo on Pawnee Fork, on the ground where Larned is now situated, with a party from Bent's Fort. They were just on the point of crossing the Trail at the mouth of the Pawnee when the soldiers from Fort Leavenworth came along, and from them Hobbs and his companions first learned of the murder of Chavez on Cow Creek. As the men who were out hunting were all familiar with every foot of the region they were then in, the commanding officer of the troops induced them to accompany him in his search for the murderers.

Hobbs and his men cheerfully accepted the invitation, and in about four days met the band of cut-throats on the broad Trail, they little dreaming that the government had taken a hand in the matter. The band tried to escape by flight, but Hobbs shot the doctor's horse from under him, and a soldier killed another member of the band, when the remainder surrendered.

The money, about twelve or fifteen thousand dollars,[24] was all recovered, and the murderers taken to St. Louis, where some were hung and some imprisoned, the doctor escaping the death penalty by turning state's evidence. His sentence was incarceration in the penitentiary, from which he was pardoned after remaining there two years. Hobbs met the doctor some years after in San Francisco. He was then leading an honest life, publishing a newspaper, and begged his captor not to expose him.

The money taken from the robbers was placed in charge of Colonel Owens, a friend of the Chavez family and a leading Santa Fe trader. He continued on to the river, purchased a stock of goods, and sent back the caravan to Santa Fe in charge of Doctor Conley of Boonville, Missouri.