The Index of Biological Integrity (IBI) is arguably the 'most widely used and effective' multimetric index of stream condition. The purpose of this project was to calibrate the IBI, which has already been proven effective, for the upper Bulkley River watershed. The IBI was calibrated by testing the response of the individual metrics across a gradient of human influence, from uninfluenced to heavily influenced, and by establishing expectations for local streams based on reference (uninfluenced) streams.