Escapement index counts of chinook salmon Oncorhynchus tshawytscha have been conducted in streams of Northern Cook Inlet Management Area since 1958. Spawning chinook salmon have been counted from both helicopters and fixed-wing aircraft. Eighty-eight streams have been documented to contain spawning chinook salmon in the Northern Cook Inlet Management Area. Aerial escapement index counts are conducted on 17 streams on an annual basis (1977-1996), and it is believed that 50% to 60% of the chinook salmon production of Northern Cook Inlet returns to these 17 streams. Escapement counts from weirs were compared to escapement index counts; index counts averaged 46% agreement with weir counts. Four years of paired escapement index counts from three observers had 93% agreement.