Here's an image of a steelhead being released into the cold and clear Salmon River about 60 miles north of Sun Valley, Idaho. It is the longest anadromous steelhead run, over 900 miles in length, in the continental United States. The Upper Salmon River also hosts a summer Chinook and Sockeye run. The steelhead start to show up in the upper Salmon River some time in mid to late March and the season stays open through April and closes May 1st of each year.