The Bow River In Winter Author: Kurt Chenuz    The Bow River starts a journey to the sea from its headwaters in the Canadian Rocky Mountains. Beginning as a trickle beneath the Bow Glacier its volume rapidly increases as it collects water shedding from each mountain that it passes.  Momentum begins to mass as it descends the steep confinements between the mountains. The turbulence created while recklessly crashing downward allows oxygen to mix with the water in high concentrations.   This arterial mixture feeds the life beneath the surface and gives the river a characteristic rich green colour. Bow River in Winter Emerging from the mountains, the Bow slows and takes a breath as it reaches the softer soil of the western Canadian prairies.   It matures as it meanders its way through the heart of the City of Calgary. The river carries on across Alberta where over thousands of years it has etched out a valley through the prairie landscape. The river valley walls seemingly  pushed aside the prairie and opened the earth to make room for the Bow to create and nourish a forested wildlife sanctuary. As the river flows eastward it gains stature and collects other great trout rivers from the Canadian Rocky's south-eastern slopes. The Highwood River collects the Sheep River and joins the Bow River just downstream of Calgary. Further to the south, the Livingstone, Castle, and Crowsnest River are absorbed by the Oldman River. The Bow River eventually looses its identity as it converges with the Oldman River becoming the South Saskatchewan River. The river heads north-east through Alberta and Saskatchewan bringing much needed water to the prairie farmlands. The waters of the Bow River, now part of a greater water system, eventually empty into the Hudson Bay. It is the part of the Bow River from the Calf Robe bridge in Calgary to Policeman Flats boat launch that winter fly fishing is most productive.  During the winter months, there are two factors that contribute to the ability to fly fish this part of the Bow River.   The warmth from a city of over a million people, coupled with a warming weather phenomenon known as a Chinook, keep the waters open year round. The warming effect of the city is always present; however, Chinooks only occur periodically throughout the winter months.  They can swing the air temperature in a 24 hour period by 40ºC. A Chinook is created by warm air massing from the Pacific Ocean. The warn air drifts eastward and spills over the Canadian Rocky Mountains on to the Foothills District of southern Alberta. The event causes a significant warming swing in the winter air temperature and teases people into believing that an early spring has arrived.  The warm air appears to push the clouds eastward away from the Rocky Mountains.  It clears the skies by folding back the clouds and forming what is know to the locals as a Chinook arch. When the weather conditions are right, fly fishing for trout that are holding up deep in their wintering holes, can be very rewarding.  Chinook Arch in the Background With the appropriate clothing one can be quite comfortable even while wading in the water. Fortunately, it is generally not necessary to wade in the water. The river's edge is usually covered with a thick ice shelf.  The shelf makes a nice path to walk on and an excellent casting platform. Taking a wading stick to check the thickness of the ice is a good safety rule. As well, avoid walking on ice where the water below the ice is more than a foot or two.  Many a fly fisherman look forward to the winter fishing offered by the Bow.   Others prefer to remain in their dens tying flies and maintaining their fly fishing equipment in anticipation of an early spring.  Whatever your choice might be, winter Chinooks offer the fly fisherman an opportunity to fish the Bow River for trophy trout year round.