The objective of this report was to summarize results of a series of recent laboratory studies conducted to evaluate the effects of chromium on chinook salmon. Individual studies focused on determining the relationship between exposure concentration and toxicological response for a range of life stages including fertilization, egg through swim-up (early life history), parr health, and avoidance-preference of juveniles. Study designs were representative of possible exposure scenarios in the Hanford Reach of the Columbia River.