Polly Bartlett, also known as the "Murderess of Slaughterhouse Gulch,"  is often credited as the first serial killer in Wyoming. According to legend, Polly Bartlett and her father, variously named Jim, John, or Stephen Bartlett in different versions originated from Ohio, where they ran a saloon and practiced early schemes of seduction and robbery. Polly allegedly lured wealthy male patrons, isolated them under the guise of intimacy, while Jim robbed them blind. Their criminal partnership allegedly grew more ambitious, leading them westward to the Wyoming Territory during the gold rush.

There, east of South Pass City, they supposedly constructed a frontier inn or lodge strategically positioned to intercept miners, travelers, and businessmen. The plan was sinister: offer warm meals and lodging, lace the drinks with arsenic, rob the poisoned victims, and bury their bodies on the property.

Polly and her father Jim Bartlett operated a lodge during the gold rush era in 1868, not far from South Pass City. They targeted men who traveled with valuables, especially those carrying gold or business documents. Polly would serve them food and whiskey, both allegedly poisoned with arsenic. After the victims died, Jim would bury the bodies on-site, while the two claimed that Native American raids or outlaws were to blame for the disappearances.

Their alleged first victim, Lewis Nichols, was said to have carried $4,000 in cash, a considerable fortune at the time. That money supposedly financed the construction of their "death lodge." Over the course of a few months, Polly and Jim were said to have murdered 22 men, with all bodies allegedly recovered from their property.

Their downfall, as the legend goes, came in August 1868, when they murdered Theodore Fountain, the son of a local mine owner. Outraged, Bernard Fountain hired detectives from the Pinkerton Agency to track down his son. After uncovering the bodies buried around the Bartlett property, the law moved in.

Polly and Jim attempted to flee. However, Ed Ford, a man who had barely escaped the Bartletts’ clutches, though his brother was not so lucky, racked them down. On October 7, 1868, Ed reportedly shot Jim dead and turned Polly in.

Polly Bartlett was jailed but never faced trial. That same night, she was allegedly shot through the window of her cell by Otto Kalkhorst, a German immigrant who worked at one of Fountain’s mines and claimed to seek revenge.