The Lower Columbia River Egg Loss Model, originally created in the 1990's, was developed to predict Mountain Whitefish  (Prosopium williamsoni) egg stranding as a result of hydropower operations on the lower Columbia River in British Columbia, Canada.  The model was updated between 2010 and 2013 using results from individual river 2D hydraulic models developed for two key spawning areas and incorporates spawning timing, incubation time, dewatering time, and egg deposition probabilities as a function of time and depth.  The updated model estimated relative annual stranding rates of eggs deposited during the winter months from the two spawning areas that were believed to represent the Mountain Whitefish population of the lower Columbia River in Canada.  Results from this work provided updated tools to reduce the uncertainty related to overall reliability of egg loss estimates and will help guide future management of the Mountain Whitefish population in the lower Columbia River.