Author Mike Price, Trouts Frisco
When most of us think of winter fly fishing, thoughts of Mysis fed tailwater trout and microscopic midges tied to fluorocarbon the diameter of your hair come to mind. Although tailwater fisheries such as the Blue River below Dillon Reservoir, South Platte, Frying Pan below Ruedi, and Taylor River offer fantastic winter fishing, they can also get crowded(even in the middle of winter) to the point of throwing in the towel and heading to the pub. We are blessed here in Colorado to have a handful of lower elevation locations that often stay 10 - 20 degrees warmer than the rest of the frigid mountainous areas throughout our beautiful state. And in better news, some of these locations have freestone rivers that run through their valley floor. With the right timing and tactics, these freestones can provide outstanding angling opportunities with little or no pressure. I will cover some of these specific rivers and their individual access points in the next segment, but in this portion I want to go over the basics of fishing freestone rivers in the winter.
Timing/weather trends - This is the single most important factor in planning a winter freestone trip. Just like fishing a tailwater during winter, you need to be on the water during the warmest part of the day (usually 10am - 3pm). Once the winter sun has heated up the water column to the upper 30’s you will see an increase of midge activity and fish will be more likely to move a few inches to eat. On the other hand, thick winter clouds can serve as an insulator and keep the air slightly warmer than on a bright and sunny day. Your best shot at dry fly fishing will occur during these slightly warmer low light conditions. Midges and Blue Winged Olive Mayflies prefer to hatch in these low-light conditions, and the lack of sunshine creates longer timeframe for their wings to dry off before they can fly away. This can provide easy pickings for a lethargic trout. Keep in mind that after a major cold front, freestone rivers will take a few extra days to warm up and finding a high pressure window with consecutive nights above 20 degrees should be your goal. If you decide to fish during or just after a cold snap you will find a lot more ice in the water than feeding trout.
Rigging & Flies - Another great thing about fishing a freestone river (compared to a tailwater) in the winter months is that you can bump up your tippet size and use bigger flies on average. A great searching setup for a freestone outing would be a double nymph rig with a 3X 7.5’ leader tapered to 4X fluorocarbon, a weighted stonefly pattern such as a #8 Pat’s rubber leg or #10 tungsten 20 Incher followed by 12” - 18” of 5X fluoro to a #18/#20 Black beauty or Zebra midge. I have found in most freestone rivers with good trout populations and healthy aquatic insect life, the majority of the fish are gonna pick the larger food item over the smaller midge imitation. The reason for this is simple- more calories for less effort. Why would you snack on peanuts all day when you can have a nice bacon cheese burger for lunch and call it good. With the exception of those daily midge emergences, there is not much else drifting in freestones until late winter or early spring, when Baetis nymphs and some Caddis begin to pupate or attempt to hatch during a warming trend. On the other hand I firmly believe that when shelf ice begins to break up and larger ice chunks collide with the river bottom or bank they can dislodge any number of food items and cause a feeding frenzy. This is one reason I think a pink or red San juan worm is so effective in the winter and spring. Another very overlooked and underutilized food item in all freestone rivers is the Cranefly larva. This very large grub looking insect lives in the rocky soil of the stream side banks as well as the the river bottom. Sometimes these 2” - 3” larva will get dislodged from the bank or river bottom and when a hungry trout finds one they won’t miss a chance at this protein packed offering. The Arkansas river has a massive Cranefly population and is the first place I started to use them in my nymphing rigs. It was a fun change of pace to use 3X tippet to a size 6 Barr’s Cranefly larva and get 80% of the fish on the big fly! Another huge player in the winter and early spring is the Golden stonefly nymph. Fish will readily move a foot or more to intercept these large food items, especially when they are molting their exoskeletons in late February and March. All Stoneflies have a multi year life span and as they grow they need to shed their old skin to grow into the new one, just like a snake sheds it’s skin. When they molt, they actually crawl out from the rocks and become highly susceptible to being swept away in the faster currents, providing an easy meal for a waiting trout. When the Stonefly is molting, it’s new skin it becomes very soft and lighter in color making it even more appealing to devour.
Where to find feeding fish - Trout are cold blooded and and prefer a certain temperature of water to live in(40 - 58 degrees for most species). During the middle or latter part of the winter we will begin to see water temps hit this magic 40 degree mark with some regularity and this can create some of the most aggressive feeding we’ve seen in months. Carry a thermometer and check water temps in the winter. If you happen to see water temps holding in the 30’s, plan on most fish being very lethargic and sitting on the very bottom of the deeper runs and pools that day. Like I mentioned earlier however, some days will still see incredible amounts of midges emerging and stuck in the surface film of the water as they dry their wings. The trout will key in on this event to get a decent meal for the day, regardless of water temperatures. Look for these feeding events to primarily takes place in slower moving runs, pools and tail outs. Conveniently enough, these areas are also where it is easiest to spot the rising trout. When nothing is visibly feeding on or near the surface of the water, chances are they are hugging the bottom of a deep pool or run. You will need a fair bit of weight to get down to the fish. More times than not you need to be bouncing on the bottom and/or picking up moss on every other drift. It is imperative that you adjust your weight and distance between your indicator and flies to find the right combination. I prefer to use multiple small or medium split shots spread out in a row spaced apart to create less of a hinge in the leader. The hinge created by one large split shot or moldable tungsten can cause a delayed reaction in the indicator, therefore creating more missed strikes. Most- if not all- strikes will be very subtle so set the hook on any variation in your drift that could be a potential eat. In some deeper pools you may have to go 8 or even 10 feet of distance between your indicator and weight. Unlike fishing in the warmer months it is very important to really fish one spot thoroughly, and not move around too much. If you get a fish or two out of a deep run or pool, then chances are there are a lot more stacked up in the same spot. If things slow down or you think you have caught all the fish in that particular pool, add one more split shot or add a third fly to your rig and chances are you will pick up a few more.
In the next segment I will go over specific rivers in our area and how to approach fishing them on a month to month basis.