Reading a Stream Means More Than Looking at Currents on the Surface

By Gary Lewis

Gary Lewis Books and DVDs

When I was 11 years-old I didn't care much about fishing. Give me a BB gun or a good book to read and I could get excited. Until my Uncle Jon told me that I could learn to read a river like a book. Read a river? Now I'm hooked.

There are two ways to approach fishing a stream. The first is to look for visible fish and then to make the presentation. The second is fishing on faith. This refers to anytime when there are no fish to be seen but you know that they must be there. To successfully fish blind requires that you can guess the spots in the river where the fish are most likely to be found.

A trout needs three basic things: oxygen, shelter and food.

Oxygen. In general, oxygen in cold water is not a problem. What happens in the warmer months is that the trout's metabolism has increased and he needs more oxygen from the water around him. As the temperature of the water increases, the amount of oxygen that it can hold decreases. When the stream thermometer registers above 70 degrees, the trout are in danger of suffocating. Unless they can get to whitewater. The more turbulent the water, the more air is getting into it.

Shelter. Everything that will eat a fish (except another fish) comes from above. When a trout is a fingerling, a kingfisher might get him. A little older, a little bigger and blue herons will be stabbing their beaks at him. When he makes it to pan-frying size, then fishermen are interested in turning him into crispy brown fillets. So trout go where you and the birds can't see them. They'll hide just off the bottom of deep holes, under cut banks, sulk in the lee of a boulder or under a fallen log where a bird cannot swoop down and take them. Unless they've been spooked, they will be within easy striking distance of dinner.

Food. The current brings much of what a trout eats to him. All that most fish below a certain size need to do is to wait.

Dinner will come. But there are certain spots in a stream where the food is concentrated.

Imagine yourself sitting at a table in a busy restaurant. There is food all around you. Are you hungry? You might just go cruising from table to table picking off the choicest morsels. But that's a lot of work. Where is all the food coming from? You look around. Waiters are bringing it from the kitchen. Wouldn't it be smartest, as long as you are going to take it anyway, to intercept them as they come out? Sure, a few bites will get by you as you are eating the lobster but the small-fry need to eat too. If only so you can eat them later.

This is how a big trout thinks.

And so this is how you should think in order to hook him. Often there is a foam or bubble line that drifts with the current. This is where the careless caddis, the unfortunate ants and grasshoppers are swept and where the larger trout line up to eat. Before you make your first cast, determine which is the best spot for a trout to wait. On a smaller stream, you can often catch the best fish first by making a good cast to the best feeding lie.

But this is the easy stuff, seeing what is happening on the surface. To really read a trout stream requires that you take all the parts that make up a particular stretch of water and see how they fit together.

Imagine this spot on the Metolius. Upstream, the water froths over smooth fist-sized stones, to break into a deeper pool. On the far side, the water is shallow, a shelf of rock, just five inches of water covering it. In the middle is a deep channel sloping up on the near side. The water sweeps around in a back-eddy piling up debris over the seasons in a dark blend of bark, leaves, twigs and pine needles. Downstream, on the near side, is a log, underwater and half-buried by silt. There is a deep cut under the log facing out into the channel. At the end of the pool, the water is hastened on its way as the water shallows and the banks constrict.

You can't see the bottom here, but you can see a bulge on the surface of the water, just ahead of the tailout. There is something there. Probably a rock and that rock is protection. Protection from danger, shelter from the current, but close enough to the food-carrying current where a fish could rise up, grab a bite and ease back down. A fish could lie behind the boulder or in the dead spot in front of it. If the boulder is large enough, there could be several fish in its shelter.

There are probably trout holding on the outside edge of the submerged log as well. Upstream, the eddy swirls around giving fish more time to look at their food. Imagine going below the surface and watching the bubble line from below. Where would you go to stay out of the heavy current yet still be close enough to take the food you wanted? Where would you go when predators with sharp beaks or nine-foot flyrods came too close?

Some stretches of the Metolius, Deschutes, Fall River and Crooked River are open to year-round angling (check your regulations). This can be a great time to be on the river when everyone else is chasing birds or recovering from elk hunting.

Bring polarized glasses and don't string your flyrod until you've watched the water for some time. Now you're reading a trout stream. The story it tells you and the story you can tell later depend on what you do next.

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