A Detection Facility

Interrogation of fish is done at dams, in streams, and at hatcheries and acclimation ponds. Interrogation sites at dams are located in the adult fish ladders and juvenile bypass systems. In-stream interrogation sites include fish traps, flat plate detectors, and full-stream monitors.  
PTAGIS maintains most of the interrogation sites at dams, and other agencies operate and maintain most of the other interrogation sites.