On July 1, 1876, the first seven inmates entered the Territorial Prison at Yuma and were locked into the new cells they had built themselves. Thus began the legend of the Yuma Territorial Prison. A total of 3,069 prisoners, including 29 women, lived within the walls during the prison's 33 years of operation.

You don't have to wait until 3:10; the park is open from 9-5 daily (see hours here) so stop in and take a walk through a big piece of Old West history.