One of the inherent abilities of good anglers is to take a quick thought to the conditions (weather, water, time of year, etc) and know what habitat to target, how deep to fish, how to present the hook, and what the retrieve needs to be. That simply comes from experience and observation.
We recently fished the Bow River just downstream of Calgary and our trout radar pinged as we floated in our boat past the following riffle. There simply had to be fish there. It’s a bold statement to say “has to be”, but when you know, you know. Let’s have a look:
Our rivers experience an annual cycle in that levels and flows lower considerably late fall through winter. Habitat availability is condensed into deeper, permanent runs and pools. What you don’t see in the photo is the winter ice that covers the river 2 to 4 months each year and trout have to move to deeper water to avoid being frozen out and to avoid being scoured when the ice shelves break apart in spring. Because winter is so cold, insect activity is at its slowest point of the year – the combination of cold water and less food cause trout to be lethargic. In response, trout move to slower currents or spots where the current is broken until conditions change. When there is a shortage of such “wintering” habitat, it’s possible that a good area of current break in a river can hold dozens of trout. That’s the #1 reason most of our cutthroat trout rivers are closed from the end of October through mid June. Cutthroat have to winter in deep pools to avoid thick ice on our mountain rivers. Because there are finite numbers of pools per KM of river and because cutthroat are relatively easy to catch, one angler could literally fish out several KM of fish in a day’s ice fishing. So they’re closed during that time.
So, as we came down the Bow River, we floated a long, wide, fast bit of water that had a shallow riffle (see that brown in the river immediately upstream of us, that’s shallow gravel), followed by a sudden deeper (see the brown turn to green-blue… that’s the drop off) broken current area. This transition of color is called “tea to green” and is a classic sign of depth change. That suggested to us that wintering trout were likely still sitting in that exact spot.
Now, rather than anchoring our boat and casting, we opted to float past that water and anchor downstream at shore, hop out and wade fish back upstream, casting upstream and allowing our flies to sink to the bottom in a dead drift, drag free manner. Our flies were small, deep, and slow. We used a strike indicator, which is essentially a slip bobber, and when the indicator stopped or went down, we set the hook. We moved or caught 1/2 dozen brown trout between 2.5 to 3.5 pounds. Every single take was in the area in yellow in the adjusted image below. That is the deepest part of the run that offers the best current break and all the other great habitat features Bow River trout use.
Of course, this isn’t the only habitat available this time of the year (think long, deep runs), but those trout had to be there. It’s these target shaped spots where trout have to be that will consistently give you the best fishing, highest density of fish, and best chances to land a few trout, especially this time of the year on the Bow. This isn’t just a Bow River habitat phenomenon, nor confined to trout. This exact water is where trout and other river species (walleye, grayling, whitefish, etc) will be in most all of our rivers until river levels rise mid May, allowing/causing fish to move in response to flow.
Dave Jensen, Alberta Fishing Guide Magazine