Anglers knee-deep in Alberta's mountain streams after the First World War understood that there was something wrong. Coal mining, forestry, and irrigation were industrializing landscapes. Roads and railways brought unprecedented numbers of people to remote fishing grounds. Once home to abundant runs of cutthroat, mountain whitefish, and bull trout, the Bow, Highwood, and Oldman Rivers, and their many high mountain tributaries, were in crises. Up and down the Eastern Slopes, anglers rallied to defend their watersheds. The ensuing fish fights were not peaceful. Deep disagreement on tributary closures, open season dates, environmental protection, regulation and enforcement raged among fishers. But despite their disputed viewpoints, Alberta's anglers agreed to advocate fiercely for the conservation of their rivers and streams. Troubled Tributaries reveals for the first time the work—and the controversy—of fisheries conservation in the Eastern Slopes of Alberta's Rocky Mountains from 1900 to 1930. It is a story of passion and commitment, of the struggle to balance nature’s use and preservation, and of people coming together even when divergent viewpoints threatened to break them apart. This is the story of the first round in the great fight to save Alberta's western trout kingdoms.