Bull trout home to tributary streams in headwater areas for spawning. Site use can be influenced by habitat quality, including physical features such as stream flow, intergravel flow, hyporheic exchange, stream and intergravel-water chemistry, temperature and cover. These variables can influence survival and growth during incubation, however, the effect on bull trout spawning and incubation success is not known. I used three studies to examine the importance of spawning habitat for bull trout spawning in northern B.C. My results show that temperature is likely a key determinant of site use at potential spawning sites as well as incubation success in northern environments. Bull trout growth and yolk utilization were substantially altered [...]