[1] Mine operators found a reduction in wages the easiest way to mitigate increased costs.
[2] The silver-mine owners responded by hiring Pinkertons and the Thiel Detective Agency agents to infiltrate the union and suppress strike activity.
[2] An undercover Pinkerton agent, soon-to-be well-known lawman Charlie Siringo, had worked in the Gem mine.
Siringo was suspected as a spy when the MOA's newspaper, the Coeur d'Alene Barbarian, began publishing union secrets.
The union men eventually sent a box of black powder down the flume into one of the mine buildings.
Federal troops also arrived, and they confined six hundred miners in bullpens without any hearings or formal charges.
[4] The profitable Bunker Hill Mining Company at Wardner, Idaho had employed Pinkerton labor spies to identify union members.
[7] On April 29, 250 angry union members seized a train in Burke and rode it to Wardner, and dynamited a $250,000 mill of the Bunker Hill mine.
[10] Emma Langdon, a union sympathizer, charged in a 1908 book that Idaho Governor Frank Steunenberg received $35,000 from the mine operators.
The mine owners developed a permit system aimed at excluding union miners from employment.