Steelhead and rainbow trout are the same species, but rainbow are freshwater only, and steelhead are anadromous, or go to sea. Unlike most salmon, steelhead can survive spawning, and can spawn in multiple years.
Steelhead are highly regarded game fish and the steelhead is the state fish of Washington.
Description and Range
Steelhead can weigh 40 pounds or more, but average between 8 and 11 pounds. Steelhead also have dark spots scattered over the entire fish, including the tail, with slight to pronounced rainbow coloring.
Like chinook salmon, steelhead have two runs, a summer run and a winter run. Most summer runs are east of the Cascades, and enter streams in summer to reach the spawning grounds by the following spring. A few western Washington rivers also have established runs of summer steelhead. Winter runs spawn closer to the ocean, and require less travel time. They generally prefer fast water in small-to-large mainstem rivers, and medium-to-large tributaries.