Fly-fishing the Bull, British Columbia

Dry fly fishing the way it once was 40 years ago in Montana? Spectacular scenery, clear abundant waters, hard-fighting wild cutthroats, no-one within miles?

The Kootenai river flows south, down the Rocky Mountain Trench that divides the Rockies from the Columbia mountains, into Montana, then Idaho before it re-appears in British Columbia again to join the great Columbia river system. Along the northern edge of the Trench, clear rivers with high channel gradients plunge from the continental divide down steep heavily forested mountain canyons. The Elk, the White, the Lussier, the Wigwam and the river I had come to fish, the Bull.

The Bull is of special importance; it is dammed in its lower section, thereby creating a respite habitat above the dam for native greenslope cutthroat trout (“cutts”). In the Rockies the more vigorous rainbows are slowly displacing cutts, or in some areas rainbows are interbreeding with cutts forming hybrids (“cuttbows”). The dam has created an enclave population and a wild fishery that is as close to a natural Rocky Mountain habitat as you can get.

One of the first things you notice when you fish the Bull is the clarity of the water, due to the resistant quartzite and metamorphic PreCambrian bedrock. The water is slightly alkaline and the riverbed is a mixture of gravels, sand and hard rock supporting a perfect habitat for many water insects.  And it is the abundance of certain species of fly-life, Caddis and everywhere the cases of the stonefly were in evidence, and the clarity of the water, that determines the character of the fishing.

The cutts in the pocket water were not shy to come to the fly if the presentation was right. On four consecutive days I landed a fish on either the first or the second cast of the day. In recent times there has been little human fishing pressure, and therefore the trout are not educated by UK standards.  However there is intense predation of trout. The area is rich in top carnivores including Ospreys, Eagles, Otters and Mink. On several occasions I saw cutts that bore the talon marks of Ospreys.

And it is this significant level of predation, particularly from the air, that I think explains the character of the fishing. The water is fast moving, but everywhere punctuated by rocks and boulders or logs. The pools are very clear and some extremely deep, particularly along the canyon sections. The fish therefore prefer to hold in very small areas of slow water next to broken water, or deep in the pools. This strategy minimises the fish’s risks of being seen from the air.

Fly or presentation?

After the second day of fishing and over 50 trout caught and released (the Bull is catch & release with a maximum of two fish allowed to be killed per day - only one fly is allowed,) it became increasingly apparent that catching the larger cutts required different tactics. The cutts from the pocket water averaged 14 inches – a 16 incher was a good fish. But the larger cutts dominate the deep pools and grow on to 20 or so inches.

We targeted the larger cutts in the canyon pools, but these were a different proposition: these deep-holding trout were much more wary, having more time to inspect the offering and being more exposed in the crystal clear water. The Parachute Adams, the Griffiths Gnat, Elk Hair Caddis, so successful in the pocket water, did little to move them. We tried attractors, nymphs, wet fly on the lift, 15-foot leaders, size 6 tippets, and so on but without success. I still think about these larger cutts as I sit at my fly-tying table in the Winter. Perhaps a slightly weighted wet F fly made from grey CDC with a hint of sparkle in the body? Or perhaps it was the presentation rather than the fly? I will never know unless I go back!.

Yes it certainly felt to me like I might have been fishing Montana 40 years ago. I did not see another angler, indeed anyone else other than my fishing partner, the whole 5 days I was there over a 10 km stretch.