Only one dam? I'm pretty sure that with a one dam removal the biggest increase in habitat access and restoration would come with removing Dworshack on the NF Clearwater. If it could be one system of dams, then as mentioned, Hell's Canyon, Oxbow, and Brownlee would restore access to the greatest amount of habitat.

Wynoochee was mentioned, but only about 10 miles would be recovered. And removing Howard Hanson, which I'm beginning to think is a good idea because the Corps has totally screwed up its downstream fish passage obligation, would restore about 36 miles. These are pretty small potatoes recoveries when compared to the Snake and Clearwater.

Sg