The Lower Columbia River Steelhead DPS includes all populations of steelhead in the Columbia River and its tributaries in Washington and Oregon, from the mouth of the Columbia up to and including the Big White Salmon and Hood Rivers. It also includes the Willamette River to Willamette Falls.
The State of Oregon only monitors populations occurring in Oregon. There is one recognized population of summer steelhead in the Lower Columbia DPS. It is considered to be functionally independent.