A large scale, comprehensive computer simulation model of the Pacific coast salmon fisheries was constructed. The model is most detailed for the Washington fisheries. The computer base is an altered version of the program GAMES. Thirty-five major salmon stocks are modelled spawning in areas from the Columbia River to the Fraser River. Gill net, purse seine, sport and troll gears are represented in ten fishing locations from Oregon to southeastern Alaska. Population estiamtes are derived using virtual population techniques. Stocks are subject to natural, fishing and catch-release mortality. Migration to spawning grounds is modelled. Spawner-recruit relationships are specified by Beverton and Holt-type equations. Harvester activities modelled are number of units of gear operating, time spent fishing and relative fishing power. Harvester economics considered are fixed and operating costs and net profit from catch. Harbesters are regulated by a general regulator varying season length and minimum size limit.