Fly Fishing for Rainbow Trout

Rainbow trout might not have the visual charm of their brown trout cousin but nor do they have its ‘diva’ temperament. Rainbows don’t hide the moment conditions aren’t 100 percent to their liking and they provide a mighty scrap should you hook one. These qualities, coupled with their rapid growth and adaptability, make them popular with fly fishers and fishery owners alike.

In some respects, rainbow and brown trout are the same. They will eat at all depths, from the surface to the floor and where they are found in rivers, they will hide behind boulders, darting out to pick off food carried to them by the current. Like brownies, rainbow trout become more predatory as they age.

Less solitary than brown trout, rainbows move around in groups, so if you hook one, chances are there will be others nearby. They are also more temperature tolerant, so may be more willing to play in summer when brown trout are lying low.

How to fly fish for rainbow trout?

First, find your fish. If you’re fishing stillwaters, fish near any dam, as groups of rainbows often corral shoals of small ‘fry’ fish into a corner late in the season and devour them.

Closer to the surface, when the weather’s warm, they get wise to stands of waterside trees from which insects are regularly blown onto the water. They will also forage for food in the margins in summer and autumn. 

Dry fly fishing for rainbows requires patience as they lap the lake; your fly may have to be on the water for up to 10 minutes. 

In open water, rainbow trout will often swim just beneath the surface of the flat-water patches called ‘wind lanes,’ looking to pick off insects being blown across the surface.

Where rainbows can be found in running water, if they aren’t dining at the surface, then fish for them deep with weighted flies, especially around those boulders behind which they shelter. The current is weaker near the river bed, so big fish rest down there. Also, try the aerated water in deep pools immediately downstream of cascades.

If no joy is found at depth, don’t rule out faster-flowing, shallower stretches. They don’t deter the resilient rainbow like they do brown trout and you can sometimes take fish in water that seems barely deep enough.

While trying to spot rainbows, make sure they don’t spot you. Wear discreetly colored clothing and fish with a backdrop of vegetation behind you rather than clear sky.

What are the best flies for rainbow trout?

If fishing small stillwaters try a Black Buzzer and nymphs like the Hare’s Ear and Pheasant Tail Nymph. Let them fall through the water while you count them down and remember which number you got to when a fish first takes the fly. That gives you an idea of the depth at which the rainbows are lying.

These highly predatorial fish respond well to streamers, such as a Mickey Finn or Muddler Minnow. Again, count them down to find the key depth and then experiment with different retrieves to see what the rainbows respond to. As winter approaches, for example, they will be adding body fat by eating all they can in readiness and they won’t want to burn it off by strenuously chasing your fly, so a slower retrieve will often fare better.

If they are feeding on surface insects but you’re not sure which ones, have a selection of dry flies with you to narrow it down – a White Wulff, Hare’s Ear Emerger, Quill Gordon, Parachute Adams, or Light Cahill.

And don’t be too quick to strike: wait until the rainbow has pounced and turned back down into the water before raising your rod tip to engage the hook.

As night begins to fall when you’re river fishing, if nothing else is working, cast a big wet fly like a March Brown across and downstream and let the current bring it round.