Several State Of The Salmon datasets have been mapped to Hydro 1K.
Hydro 1K is a geographic datalayer of watersheds and streams developed by the U.S. Geological Survey EROS Data Center, derived from the 30 arc second DEMs.
State of the Salmon GIS staff appended, cleaned, and clipped the basins to the North Pacific extent area. This coverage was then edited, by manual digitizing, checking accuracy against a 1:1,000,000 streams coverage, digital elevation models, and 4th field watershed boundaries where available. This process mostly entailed eliminating erroneous inclusion and exclusion of upper stream reaches within Hydro1k boundaries. When more detailed streams were consulted in the Pacific Northwest, Hydro1k basins could have been refined further and were in the cases when it affected distribution of salmonids at the time of processing (Summer 2004). This finer resolution stream data was not used extensively to maintain a consistent level of accuracy in the Hydro1k basins dataset across the North Pacific. When finer resolution streams data is obtained for the remainder of the North Pacific, further refinement can take place.
More information on Hydro 1K is available here.