The Drumheller Strike of 1925 1925, ushered in a period of rival or "dual" unionism in Alberta's coalfields. The Drumheller miners, rejecting wage cuts negotiated by the United Mine Workers, struck in June 1925. The strike faltered because many miners continued to work and provincial police protected them. A violent police-striker confrontation on June 26 effectively ended the strike. But miners, angry with the UMW's collaboration with the coal operators regarding wage cuts, formed the rival Mine Workers' Union of Canada which battled the UMW for a decade before declaring a truce and rejoining the old union. The MWUC-UMW rivalry, though beginning in Alberta, spread to coal mines across western Canada. It also had political overtones because of the major role communists played in the MWUC.