Continuing drought conditions have spelled disaster for Winter-Run Chinook Salmon in the Sacramento River. All Salmon must swim to saltwater, but their route to the sea faces many perils. Higher than normal water temperatures in the river caused a mortality rate of more than 97% for the winter-run. A device installed on the back side of Shasta Dam pumps colder water from the bottom of the lake to keep the river cold for Salmon, but the shallow condition of the lake has made even the water on the bottom too warm. A 5-and-a-half mile stretch of the Sacramento River from Keswick Dam to the Sundial Bridge is where the majority of spawning is believed to occur. Of the more than 31 Million winter-run eggs laid in the spawning grounds, fewer than 125,000 are believed to have made it on the long journey to the delta and the ocean.