Riverscape snorkeling surveys of salmonid distribution and abundance before (2007, 2008) and after (2018, 2019) dam removal on the Elwha River, Washington

We used snorkel surveys in the Elwha River, conducted in consecutive years before (2007, 2008) and after (2018, 2019) dam removal to assess changes in fish distribution and density. In total, we counted 54,616 Chinook Salmon, Bull Trout, Steelhead, and trout (Rainbow Trout and Coastal Cutthroat Trout combined) in 22 common reaches spanning 65 river kilometers. The occupancy of juvenile Chinook Salmon, Coho Salmon, and trout was also assessed following dam removal.