Near Nelson, the Kootenay River is popular with fly fishermen for bull trout, cutthroat trout and rainbow trout. On this freestone river, you can expect to find bull trout up to 35 inches long.
The best section for fly fishing the Kootenay River via float boat is from Canal Flats down to Skookumchuck just upstream of Lake Koocanusa on the Montana border. There is a great 40km section between Nelson and Castlegar. The Slocan Pool where the Slocan River comes in is known for its huge rainbow trout. It is best in April and May, and then again in September and October. This is a scenic river valley with aspen stands and lodgepole pine.
Overall, Kootenay River is the 5th most popular fly fishing river of all 16 fly fishing spots in British Columbia.