Steelhead Run Over Bonneville Tops Records

The largest steelhead run in the history of dam counts is crossing Bonneville Dam on its way up the Columbia River. As of August 19, the count of steelhead at Bonneville topped 390,000. Most of these steelhead are of hatchery origin, however, not the wild runs that came upriver before Bonneville Dam was built in 1938. If water temperatures remain near normal in the Snake River, it is likely this steelhead run could set a record for numbers entering Idaho. Water temperature has been a serious concern because of drought and hot weather conditions in Idaho this summer. Steelhead passage over Lower Granite Dam came to a virtual standstill as water in the forebay of the dam heated up to almost 77 degrees. Temperatures have since declined in the Snake River system. Temperatures have declined in the Snake in the last few days, improving the rate of steelhead crossing at Lower Granite Dam. As the water temperature fell from 76.6 degrees to about 70 degrees, steelhead started moving into Idaho again. It is not uncommon for a thermal block to develop in the lower Columbia river or between the Columbia and Snake Rivers where the Snake is often warmer than the Columbia. The warmer water can keep steelhead from entering the Snake River. In other years of low, warm water thousands of Idaho steelhead never made it home. So far, 13,800 steelhead have crossed Lower Granite, 2,200 of those August 18-19. Catch and keep steelhead fishing starts September 1 except on the Clearwater River where the keep season begins October 15.