The late Frank McCarthy was a member of the Cowboy Artists of America and a great painter. He’s probably best-known for his action-packed renderings of the Old West such as are seen on film posters, magazine covers, advertisements and paperback covers.
Chasing a stagecoach was mostly the stuff of Hollywood because it added more drama to the event. Remember Hollywood is in the entertainment business so it looks better on screen to have a chase whether it be a train or a stagecoach.
It’d be especially tough for a horse to chase a train or even a stage for any distance. Stage robbers usually tried to find a convenient, secluded place to pull a robbery. A hill or long slope was preferred. They also wanted a place of concealment to set up the ambush. Sometimes they would fire a warning shot to halt the stage and sometimes they would shoot the shotgun messenger.The latter was a dangerous choice because murder is a capital offense.
A steep uphill grade was also a good place to hop a train. One of them could make his way up to the cab and stick the barrel of his pistol in the engineer’s ear. They would usually picket their horses and stow their dynamite a couple of miles ahead then walk down the hill to a spot where they could stop the train, separate the express car and engine from the passenger cars and force the engineer to pull ahead to the preplanned place where they could ransack the safe without interference from the passengers. Train robbers usually put a barricade of some kind on the tracks or used a lantern to signal the engineer there was trouble ahead. Speaking of dynamite, train robbers, including Butch Cassidy, should have honed their skills on blowing a safe before pulling the heist. The Union Pacific frowned on outlaws blowing their express cars to smithereens.
Cassidy is credited with using relay horses along the way, oftentimes by friendly ranchers who hated the railroads because of exorbitant prices for shipping. Since posses didn’t have such luxuries, their horses played out and they had to give up the chase. They also had friendly folks to tell the posse “They went thataway, when they went thisaway.”