While several salmon stocks are still endangered, data show that the Columbia and Snake River are producing significantly improved numbers of juvenile salmon. According to NOAA Fisheries, “…the Columbia and Snake Rivers may now produce more juvenile salmon than they did prior to dams and development, when hatchery fish are included.” Adult returns also saw significant improvements in the last decade, but poor ocean conditions reduced those numbers once again. Like the Snake River, undammed rivers from Southern Oregon to Alaska are seeing worsening returns of adult salmon, which is a cause for concern.
NOAA Fisheries Fact Sheet: Southern Resident Killer & West Coast Chinook Salmon
University of Washington–Columbia Basin Research–Data Access in Real Time