Man-made barriers block the upstream passage of migrating organisms in many river systems. Removal or circumvention of these barriers is a major restoration tool used throughout North America to restore fragmented river landscapes.  It is generally assumed that such actions will benefit stream biota; however, the biotic response has rarely been documented. Landsburg Dam on the Cedar River, WA had blocked upstream migration of Pacific salmon, and number of other native fish species, from 1900 until 2003, when a fish passage facility was installed.  We quantified fish density and composition in about 25 km of habitat for two years before and four years after barrier circumvention.  Resident trout densities before the fish ladder increased from downstream to upstream ranging from 0.01 to 0.12 fish/m². This pattern was reversed after the ladder with the greatest increases occurring in reaches above the dam. The return of salmon to the Cedar River has led to a redistribution of fish largely due to the addition of juvenile coho salmon and local increases in resident trout density.