You can count on caddis to be present on most Alberta trout waters, including mountain cutthroat trout streams, spring creeks, and especially the Bow River in Calgary.
The caddis hatches on the Bow are prolific, ever-present, and intense in both duration and daily occurrence. Bow River rainbows and browns gorge themselves on caddis. The mid May hatch is an important event in providing energy to skinny late-winter browns and for energy depleted rainbows returning from the Highwood and Sheep Rivers post-spring spawn. Summer trout simply grow fat on caddis.
Trout love caddis so much that even during intense mayfly hatches - where only the most precise mayfly pattern seemed to work - an elk hair caddis will actually be favoured. If asked to pick one dry fly pattern to fish all summer, many experienced anglers would choose a caddis imitation. I’ve fished many days without seeing a caddis but still caught fish while blind fishing likely water with an elk hair caddis.
Given the above, you’d think any old caddis pattern would work. Like all hatches, however, there are subtleties to what trout are keying to and how they react. While trout appear to be contently feeding on naturals, it’s imperative to understand the differences in their targets and to have a selection of caddis patterns, particularly when casting to picky fish.
Be observant: Sit down on the bank and watch those damned trout before you make a cast. Watch to see what the fish are actually eating. Yes, there’s a caddis hatch going on right now, but what are the caddis doing on the water, and how are trout reacting to caddis as they move over their feeding lane. Moreso – are the targeted caddis moving/skittering across the trout’s feeding window or are they dead drift or spent? Are the caddis actually on the water or hovering above it? There’s a massive difference between the subsurface boils of trout targeting emerging caddis while adults are actually flying in the air than the aggressive pops of trout smashing the surface to eat a skittering, egg laying adult. Further, you may confuse subtle rises and takes from large trout as mayfly feeds, yet upon further examination you see spent and splayed caddis gently drifting through. Treat each rising fish individually and continue to monitor its rises and actions as you work – it may change its target caddis activity.
Work slowly and cautiously. Bow River trout targeting caddis can often be feeding in mere inches of water in the extreme recesses of the river’s edge. I’ve seen many people storm into the river during a hatch, just to spook fish with loud, abrupt movement. Move slowly into position. Watch your approach speed and step energy and frequency. Keep it slow. If you move faster than 5 or 6 steps a minute, you could well be moving too quickly.
Be willing and prepared to change patterns. Just because the fish were eating skittering caddis an hour earlier doesn’t mean they remain so. If you notice subtle boils and wakes behind your dry fly, you’re likely being refused. That could be the pattern or your drift, but if you have several drag-free drifts in a row (including checking for micro-drag), change your fly.
Experiment: Try different patterns at different times. Just because you are catching trout on an elk hair caddis doesn’t mean you won’t experience greater success with an “X-Caddis”. It’s a subtle change but again, if trout start to key on spent caddis the lower riding X-caddis will be that much more successful. Further subtleties can work as well: trim the underbody fibers of an Elk Hair Caddis so the bottom of the fly sits flush with the surface film. The palmered hackle frequently causes the pattern to land and lay on its side or simply float too high.