Postcard published in 1910
The mine was the object of legal and physical attacks from the forces of copper king F. Augustus Heinz who claimed that Pennsylvania's ore veins apexed in his neighboring Rarus Mine. Heinz prevailed when the courts upheld his "apex theory" in 1905 but sold out to the ACM a year later.
The Pennsylvania was the scene of the second deadliest mine accident in the history of the Butte district. On February 14, 1916 a fire in the mine's ventilation shaft claimed the lives of 19 miners and 2 would be rescuers.
The Pennsylvania was consumed after open pit mining began in Butte in 1955. The mine's location now lies under the toxic waters of the Berkeley Pit.