The Wyoming Territorial Prison was the only prison that ever held Butch Cassidy.

Born Robert LeRoy Parker to a Mormon family in Beaver, Utah, Parker changed his name to Butch Cassidy when he started his life of crime. During his notorious career, questions arose as to whether he was a modern-day Robin Hood or wild criminal, as he was known for giving back to those who gave him refuge from the law.

He served time at the Wyoming Territorial Prison from 1894-1896 for stealing horses. It was the only prison to ever hold him. The Wyoming Territorial Prison was constructed in 1872 and began accepting prisoners in 1873. In 1890 Wyoming became a state and the operation of the prison was transferred to the State of Wyoming. Prisoners began being transferred from the prison in 1901 to the newly built Wyoming State Penitentiary in Rawlins, Wyoming. The Wyoming Territorial Prison was closed in 1903 and today is a state historical site.