The Arizona Copper No. 4 or more affectionately named, La Nena"was built by the H. K. Porter Company of Pittsburgh, Pennsylvania in 1887 under works number 814 for the Arizona Copper Company to haul ore trains from the Metcalf mines on the Coronado railroad
Even though No. 4 was ordered by the Arizona Copper Company to be part of their fleet, it actually went to work for their neighbor, the Detroit Copper Mining Company instead. It became their No. 2 engine and had been heavily modified over the years. When the locomotive was about to be retired from service, George Gamble, the engineer of the locomotive, bought the engine from the scrapper to keep it from being destroyed. He later donated it to the Adobe Mountain RR Museum in Phoenix, AZ.
Today Arizona Copper No. 4 still resides at the museum with fresh coat of paint proudly displaying her correct number and original livery.