Fly fishers who fish lakes need to understand how a lake functions. Many years ago, while guiding Eagle Lake, I had a chance to work with the master, Jay Fair. He taught me how to analyze a lake. Only Jay could teach this way: I worked the boat with a small trolling motor on it while he fished. He would describe the area where we were and tell me why fish would be in a certain spot. Then he would cast and hook a fish. He would turn and look at me and say, “See, I told ya.” Then he would make me net and clean the fish. Those lessons have stuck with me, and they are simple and ensure my outings will usually be successful.
Understanding a Lake
You’re looking for feeding fish — right? So first, you need to understand how the food supply works in a lake. The food producers are the shoals and other areas that the sun can reach. The sun drives food production. Even though midges live 20 to 30 feet deep, they still need the sun to produce their food. So anywhere in the lake that the sun can penetrate will produce food.
In large lakes such as Almanor and Davis, shoals are a great place to fish, especially the transition zone from the shoal to deep water. Shoals don’t occur just around the shoreline, either. They are sometimes found offshore, and might be an island at low water and a submerged knoll at high water.
Shoals can be weedy, rocky, covered in sunken logs, or a combination of these things. Damselflies, caddisflies, mayflies and other creatures live in this sunny area. So do small fish trying to grow up. They hide from predators in the cover. Larger fish travel into these shoals to forage for food.
It’s important to understand that fish in still waters, trout especially, are often on the move. They’re looking for food, certainly, but they’re also seeking comfort, which basically means cold water. (At certain times of the year they also move in order to find inlets in which to spawn.) So while the penetration of sunlight is essential to food production, water temperature is key. A trout doesn’t like to eat in hot water. It’s uncomfortable. You won’t find fish in water where the temperature is too high, even if — or because — the sun can reach it. Rainbows will be the first to leave. Usually, if the water gets around 58 to 60 degrees, the rainbows are gone. Browns can handle heat better, and they usually don’t abandon warm water until it gets past 60 degrees. If the food in warmer water is plentiful and attractive, they will go in for a quick bite and then return to colder water. Most of the time, though, the fish will seek colder water with an equal or better food source. That’s one reason why on bigger lakes, fish also may be following baitfish in deeper water. In smaller lakes, you may find fish feeding in deeper and colder water on drowned insects. The difficulty, though, is that it is hard to determine where these deeper feeding zones might be situated. You will have better success if you understand the lake’s resident aquatic insects and their habits, particularly where they live and when and how they transition between life stages. If you know these things, you will know what fish are eating in any given spot. On the shoals of Lake Almanor, it could be the Hexagenia mayflies that swim to the surface. Where a creek runs into the lake, it could be caddisflies and stoneflies.
In addition to places with light penetration and cold water, you need to look for places that give cover to fish. If the shoals are shallow, these could be places that are a couple of feet deeper in the middle of the flat. We call these “potholes.” Cover also is provided by dropoffs next to the shoal, which also provide access to cold water.
When you have sunlight penetration creating a food source, cold water, and cover, you have the three basic conditions that determine where feeding fish can be found. You then can look for places that have additional amenities that fish like, such as a stream coming in or a spring in the area, maybe even just a floating log or weed bed.
Fishing Tactics
You have now figured out where the fish may be. Perhaps you’re using a fish finder to explore the lake and can see the structure of the bottom, with fish holding on that structure. Now you need to decide how to fish that area.
Based on your understanding of the food source, you know what the fish could be eating, or at least you have a good idea what it could be. If it’s an insect, you know how that insect hatches — whether it rides straight up to the surface, like a midge, or swims to the surface, like a mayfly, or crawls out of the water onto a branch, like a damselfly. So the correct method of fishing is to match the insect you are trying to imitate. But you knew that. If you understand how lakes function, though, you’ll also know where to fish.
Let’s say you are on a big mud flat that is 15 feet deep. The fish have access to cold water, because there is a drop-off going to deeper water — 25 feet. You see no fish feeding on the surface, but there are midges hatching here and there. There is a little wind, just enough to ripple the water. You could fish with a sinking line with searching patterns (Woolly Buggers, leech imitations, and such), or you could fish deep under an indicator with midge imitations. This would be my pick. The wind will jig your flies just enough to give them movement.
But where should you fish this setup? If you understand lakes, you’ll fish the transition zone from the shallower water to the deep drop-off. That’s where the fish will be.
Consider another situation. You’re in a pontoon boat, and there is a log on the bank that extends into the water. It is so old that it lies on a shoal that shelves into deep water. On one side of the log is a weed bed, and on the other side is a big boulder. The deep water is about 20 feet from the bank, and it’s about 25 feet deep. There are caddisflies and damselflies flying around, and no fish on the surface. The wind is still, and the lake is calm. How do you fish a complex situation like this?
If you understand how lakes work, you’ll fish all the transition zones: shallow to deep, the log, the weed bed, and the boulder. I would position my pontoon boat parallel to the shoreline. Then I would fish a sinking line with a small damselfly nymph or an AP Nymph, first casting to the shoreline and working my way out to deeper water, fanning my casts three feet or so from each cast I already made. Fanning casts in this manner covers water quickly and thoroughly, whatever method you’re fishing, whether it’s dry flies or stripping streamers. If fishing subsurface, I vary my retrieve from slow to quicker strips and use different angles of retrieve, which will give the fish more opportunity to see the profile of the fly. I always start with slow retrieves and use my fins to kick to add movement.
You can’t catch fish if you can’t find them, and lakes present a puzzle to many anglers. If you understand how a lake functions with regard to its populations of fish and their food sources, you’ll have a much easier time solving that puzzle and figuring out where and how to fish in any stillwater situation.
