Fish and benthic macroinvertebrates were sampled at 38 sites on streams with existing or historical placer gold mining activity near Dawson City in Yukon Territory, Canada. Placer gold mining gradients previously developed using only the number of active operations upstream of the sampling sites were refined by including data on a number of activity descriptors collected from mining records and consolidated using Principal Component Analysis to characterize the mining operations and account for variation among them. Several approaches to generating placer mining gradient descriptors were carried out and compared. Correlations between the level of placer mining activity upstream of sampling sites, their biotic communities and suspended sediment were calculated and analyzed. We found significant correlations between the level of mining activity and benthic macroinvertebrate community diversity.