The present study compared selenium in fish tissues from flowing water systems near three west-central Alberta mountain cola mines in the upper McLeod and Smoky River systems to the toxicity effects thresholds developed by Lemly (1996). Overall, data for fish tissues collected in 2000 and 2001 by Alberta Sustainable Resource Development showed that selenium concentrations in rainbow and brook trout were usually greater than toxicity effects thresholds in the exposed streams compared to reference streams, particularly in the tissues of fish collected from waters draining the Luscar and Gregg River mines. General patterns for selenium concentrations int he remaining fish species sampled (bull trout, mountain whitefish, Arctic grayling, and longnose sucker) compared to effects thresholds were not always as apparent. This was to some extent due to the potential influences of spawning migrations of mountain whitefish and bull trout among the exposed and reference sampling locations, and the limitations of the datasheet.