Later Doc wound up in Las Vegas, New Mexico where he got into an argument with a local gunman named Mike Gordan. The argument inevitably lead to a gunfight in the street and Gordan was left dead. When a lynch mob formed Holliday hightailed it back to Dodge City to find that not only was Wyatt Earp gone, but Kate was no where to be seen.

Learning that Wyatt had headed to Tombstone, Arizona to a new silver strike, Doc headed in the same direction. Unknown to Doc, "Big Nose” Kate was also in route to the new boom town of Tombstone and the two ran into each other in Prescott, Arizona. Doc was winning heavily at the tables and pocketing $40,000 in winnings, Kate was happy to keep him company. In the early summer of 1880, the two reached Tombstone.

Shortly afterwards, Kate was running a boarding house in Globe, Arizona, some 175 miles away from Tombstone. However, she was known to often stay with Doc when she visited.

Many times when "Big Nose” Kate visited Holliday, they were known to have frequent arguments, most of which were not serious until Kate got drunk. Often, her drunkenness would escalate to abuse, and in early 1881, Doc had finally had enough and threw her out.

On March 15, 1881, four masked men attempted a hold up on a stagecoach near Contention and in the attempt, killed the stage driver and a passenger. The Cowboy faction of Tombstone immediately seized upon the opportunity and accused Doc Holliday of being one of the holdup men. The sheriff who was investigating the hold-up, found Kate on one of her drunken binges, still berating Doc for throwing her out. Feeding her yet even more whiskey, the sheriff persuaded her to sign an affidavit that Doc had been one of the masked highwaymen and had killed the stage driver.

While Kate was sobering up, the Earps were rounding up witnesses who could verify Doc's whereabouts on the night in question. When Kate realized what she had done, she repudiated her statement and the charges were thrown out. But, for Doc, this was the "last straw” for Kate, and giving her some money, he put her on a stage out of town.

From 1882 until the time of his death in 1887, Doc Holliday was in Colorado. During this time, Kate was apparently also in the state, at least part of the time, as her brother owned property in Glenwood Springs. According to some reports, Doc may have actually spent time with Kate and her family as her brother's home was very near to the Sulfur Springs that Holliday visited to try to help his tuberculosis.

Kate stayed in Colorado until after Holliday's death.