This file contains a representation of 3rd order watersheds developed for the 1:50,000 BC Watershed Atlas with each watershed polygon coded for occurrence of freshwater fish species (including anadromous salmon in their freshwater stages). The initial fish species codes for presence/absence in each watershed were derived from an GIS overlay of fish species occurrences within broadly defined fish regions for BC. This overlay of fish ranges describes the occurrences of fish species in 30 regions throughout the province. These broad species ranges were derived from McPhail and Carveth's 'Key to Freshwater Fish of BC' and refined further based on the most current expert opinion. Coding for watershed polygons based on this expert opinion was originally: 0= out of species range; 4 = core range; 5= introduced range; 6= peripheral range; 9= estuarine polygons only. A further refinement of watershed fish species coding was developed from actual observations of fish species in the lakes and rivers of British Columbia. This data comes from a number of fish inventory sources. Watersheds with known records of occurrence for each fish species were consequently recoded as such: 4, 5, 6, 9 now equal '1' if a museum record, and, 4, 5, 6, 9 now equal '2' for a less reliable record, and, 0 now equals '8'. for an out-of range record