[1] Mine Owners' Associations were often formed for the purpose of fighting against union organizing drives, but smelter trusts and railroad syndicates were also a concern.
As in Coeur d'Alene,[6] mining companies in the Cripple Creek District that made agreements with unions were shut down by military force.
The motivating reason was a WFM union organizing drive in Telluride, and similar efforts in other parts of Colorado.
The SJDMA granted itself the power to prevent any of its members from coming to an agreement with the miners' union that would accept reduced hours or increased wages.
[11] This inflexible decision helped to create conditions that resulted in a series of bitter and bloody strikes throughout Colorado's mining communities.
The MOAs sometimes issued work cards to miners who were required to renounce the union as a condition of employment.