November 6, 1908, Butch Cassidy and The Sundance Kid were gunned down in South America. 110 years later, the demise of the infamous Wyoming outlaws remains shrouded in mystery.

Robert Leroy Parker was given the nickname Butch while working in a Rock Springs butcher shop. He later adopted Cassidy as an alias and embarked on a daring series of robberies that made him one of the most notorious bandits in the west. In 1894, he was arrested for stealing horses in Lander and served time at the Wyoming State Prison in Laramie.

After he was released, Cassidy formed the "Wild Bunch" with Harry Longabaugh, who had earned the nickname "Sundance Kid" when he was caught stealing in the town of Sundance. Between train and bank robberies, the outlaws often hid out at the Hole-in-the-Wall, a secluded pass in the Bighorn Mountains near Kaycee.

In 1901, Cassidy and Longabaugh fled to South America and avoided capture for nearly a decade. On November 3, 1908, they robbed a courier and hid out at a boarding house in San Vicente, Bolivia. Three days later, the house was surrounded by a Bolivian cavalry unit and a gunfight broke out. The bodies of Cassidy and Longabaugh were later discovered inside the house.

Or were they?

Some historians believe they survived the shootout and returned to the United States. According to one popular theory, Longabaugh settled in Utah and adopted the alias William Henry Long. Others speculate that Cassidy underwent plastic surgery and was later seen visiting his grandmother in the town of Baggs, near the Wyoming - Colorado border.