Table 22 to Part 226 - Hydrologic Units and Counties Containing Critical Habitat for Lower Columbia River Steelhead, and Dams/Reservoirs Representing the Upstream Extent of Critical Habitat

Hydrologic Unit nameHydrologic Unit numberCounties1 within Hydrologic Unit and within range of ESUDams/ReservoirsMiddle Columbia-Hood17070105Hood River (OR), Skamania (WA)Lower Columbia-Sandy17080001Clackamas (OR), Clark (WA), Multnomah (OR), Skamania (WA)Bull Run Dam2Lewis17080002Clark (WA), Cowlitz (WA), Skamania (WA)Merwin DamLower Columbia-Clatskanie17080003Clatsop (OR), Columbia (OR), Cowlitz (WA), Skamania (WA), Wahkiakum (WA)Lower Cowlitz17080005Cowlitz (WA), Lewis (WA), Skamania (WA)Lower Columbia17080006Clatsop (OR), Pacific (WA), Wahkiakum (WA)Clackamas17090011Clackamas (OR), Marion (OR)Lower Willamette17090012Clackamas (OR), Columbia (OR), Multnomah (OR), Washington (OR)1 Some counties have very limited overlap with estuarine, riverine, or riparian habitats identified as critical habitat for this ESU. Consult USGS hydrologic unit maps (available from USGS) to determine specific county and basin boundaries.