Interrogation Site Metadata

This site monitors the Cascades Island fish ladder at Bonneville Dam. Though this ladder has an exit above the dam into the forebay, picketed leads generally route traffic into the Upstream Migrant Transportation (UMT) channel that leads to the Washington Shore ladder. Fish detected at BO2 and heading upstream would be expected to be detected at BO3 and then BO4 afterwards, unless the UMT is closed, in which case they will exit into the forebay above Cascades Island. The original antennas were installed in the weir orifices below the UMT in 2002. In 2018, two antennas were installed in the lamprey passage structure that exits into the forebay above the island. Beginning in February 2022, the original weir orifice antennas were retired and four new antennas were installed; two antennas monitor the UMT entrance and two antennas at the counting window. The counting window antennas will only receive traffic if the UMT is closed and ascending fish pass by the counting window and exit into the forebay.

Current Operations