This is an electric boxcab engine on display at the Anselmo Mine in the town of Butte, Montana, USA. It is part of the World Museum of Mining collection in Butte.

This locomotive was built in December 1914 by General Electric and was used by the Butte, Anaconda and Pacific Railway to head ore trains from the Anselmo Mine in Butte to the town of Anaconda, Montana.

Info. from museum signage: "The Cow and Calf. Engine # 47 and its T-1 booster [= just off the left edge of the above photo] represent one of the first heavy-duty, direct current electric locomotives built in America. These engines made history representing the importance of electricity, copper and transportation to Industrial America. In 1914, General Electric provided the booster, which could be coupled to a box cab to distribute its power to more wheels for better traction in low-speed service. This engine and booster affectionately called the Cow and Calf."

"The great electric experiment ended in 1967 when the B.A. & P. replaced electric engines with diesel. Retired B.A. & P. Ry. men Leno Bazzanella and Kevin Shannon restored the Cow and Calf to their original state."

Butte, Montana was the world's # 1 producer of copper for many decades. Butte has often been called the "Richest Hill on Earth". One large open-pit mine, the Continental Pit, still mines copper-molybdenum ore. The copper in the Butte Mining District occurs in the form of sulfide minerals in hydorthermal veins hosted by Cretaceous-aged quartz monzonite. Ore mineralization occurred at ~66 to 62 million years ago, during the latest Cretaceous and earliest Tertiary.