In 1867, the Union Pacific Railroad barreled through the area and established a water station utilizing the nearby spring for its steam powered locomotives. The railroad named the stop “Big Springs,” from which the town would later take its name.

Years later, in the summer of 1876, Texas cowboys, Sam Bass and Joel Collins would make their way to the area, driving a herd of cattle to the northern markets. However, after they sold the cattle for some $8,000, rather than returning to Texas and handing the profits over to the ranchers who had hired them, the used the money to take up gold prospecting in the Black Hills of South Dakota. Having no luck and completely out of money, they then turned outlawry.

The pair, along with several other desperados, including Jack Davis, Tom Nixon, Bill Heffridge and Jim Berry, began to rob stage coaches. Over the next several months they held up seven stages, becoming known as the "Black Hills Bandits." Four of these robberies was directed at the same stage line – the Deadwood Stage. On a fifth attempt on March 25, 1877, the outlaws killed the stage driver, Johnny Slaughter. At the sound of the shot, the horses bolted, running towards Deadwood, some two miles away. Folklore has it that the runaway stage was stopped by none other than Calamity Jane as it entered Deadwood.

The gang soon decided that their profits from stage coaches robberies was too low and turned their attention to the more lucrative business of robbing trains. Making their way to the isolated station at Big Springs, Nebraska, their first train robbery took place on September 18, 1877. Capturing the station master, John Barnhart, and destroying the telegraph, they forced him to signal the eastbound express train to stop.
 

At 10:48 p.m., the six bandits boarded the train. Finding only $450 in the mail car safe, they then went to rob the larger safe but it had a time lock preventing it from being opened until the train reached its destination. Though they beat the express messenger brutally in an attempt to get him to open it, the messenger was unable to. However, the outlaws continued to search the train car, finding some wooden boxes, which revealed $60,000 worth of freshly minted $20 gold pieces. Why these were not in the safe is unknown. The bandits then began to systematically rob the train passengers. In the end, they escaped with the $60,000 in freshly minted gold coins, $450.00 from the mail car safe, and about $1,300.00 and four gold watches from the passengers.

Splitting the money up six ways beneath the “lone tree” east of Big Springs, the outlaws split up into pairs, each heading in a different directions.