Light and Ultralight: Fly Rods for Small-Stream Trout

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Fly fisherman Greg McReynolds fishes a light fly rod for backcountry trout near Yellowstone National Park in eastern Idaho.

Fly fisherman Greg McReynolds fishes a light fly rod for backcountry trout near Yellowstone National Park in eastern Idaho. 

Fly fishers who love venturing into backcountry locales in search of wild trout generally do so with lighter gear and with the understanding that smaller fish might be on the menu. 

For me, it’s a holistic experience, punctuated by the chance to fish amid stunning backdrops and away from crowds of other anglers. 

Yes, the quarry may be more diminutive. But nothing beats the experience of plucking stunning, high-country or remote-country trout from cold, clear water. 

It’s an intimate endeavor, both with the fish and with the landscape. That I’m part of a smaller fly-fishing community that makes the effort to chase small-water trout is but a bonus. Rarely do I have to stand shoulder-to-shoulder with another angler. 

Welcome to light-weight and ultra-light-weight fly fishing! 

Corey standing in a rock holding a rod fishing in the river.
Angler Corey Fisher chases trout in Utah with a 3-weight rod in response to intimate fishing conditions.

Why choose lighter fly rods?

For the small-stream fly fisher, the journey is nearly as important as the destination. Tools of the trade are generally smaller and more tuned in to precision and finesse rather than backbone and sheer “fighting power.” 

Lighter fly rods are the name of the game for backcountry anglers. Even among small-water devotees, there are important choices to be made while selecting the right fly rod for the experience. 

Man fishing on the creek surrounded with grass.
Light fly rods are made for tight quarters, like this little stream in southern Montana.

What are light fly rods?

First, you have to understand that fly fishing is full of weights, diameters and measurements that are about as random as the Imperial measurement system itself. For many of us, they only make sense because that’s all we’ve known. 

Second, when determining the “weight” of a rod, you need to know this: the actual weight of a rod doesn’t have anything to do with how heavy or how light the rod is. Rather, a rod’s weight is determined by the weight of the fly line it can reasonably cast. 

So, the question you should ask is, “How much does the fly line weigh?” 

This may seem counterintuitive to gear anglers who worry about tensile strength and a line’s “test,” or how many pounds of pressure it can endure before breaking. But, as I’m sure you’re figuring out, we fly fishers like to make things nonsensically complicated!

But here’s a simple explanation that should help you understand the physics behind fly fishing. In fly fishing, it’s not the fly that provides the weight to load the road. It’s the line. 

Here are the basics: A 1-weight fly line, according to the American Fly Fishing Trade Association, should weigh between 54 and 66 grains, with 60 grains being the “target” weight of the first 30 feet of line. For every additional “weight” of fly line, add 20 grains. In other words, the first 30 feet of a 2-weight line should weigh about 80 grains; for a 3-weight, it should weigh approximately 100 grains, and so on. 

So, a rod that’s crafted to cast a line that weighs 100 grains can be reasonably defined as a 3-weight fly rod. 

For the sake of argument, let’s assume that any fly rod lighter than the “standard” 9-foot, 5-weight fly rod can be considered a light rod — using AFFTA’s scale, that means the first 30 feet of fly line should weigh about 140 grains. 

How do you choose the right rod for the water?

Cutthroat trout caught in a small water.
Often, anglers think of the fish when they choose the weight of a fly rod. Think, instead, on the size of the water and the size of the flies you’ll cast when you go fishing. For instance, this beefy cutthroat trout was caught on a 9-foot, 4-weight rod. It was caught in small water, but open water, and the fish were keyed in on bigger terrestrial patterns.

Now, not to say that every “light” fly rod is ideal for every situation. In fact, I’m of the mind that most fly fishers, when presented with backcountry fishing conditions, often go in with too much rod for the water — and the fish. 

So, how do you pick a light fly rod for the right stream? Let’s dive a little deeper. 

First, consider the stream you’re interested in fishing. A relatively open, willow-lined meadow stream might be 20 or 30 feet across. Walking and wading such a stream can be a mix of both ease and frustration (ever bushwhack blindly through a willow thicket?). 

But, once in the water, there are relatively few obstacles and enough open canopy to confidently cast 40 or 50 feet, if needed. 

A stream like this would be an ideal candidate for a 9-foot, 4-weight fly rod. With little overhanging cover, there’s no need to “size down” to something shorter. The ability to cast to distance will be aided by the rod’s length. 

What’s more, an average 4-weight rod is perfectly capable of casting dry flies in most sizes, including larger terrestrial bugs like Chernobyls or grasshoppers when those insects are “in season.” 

Additionally, a 4-weight rod can handle small streamers and even weighted nymphs. 

But what if conditions are a bit restricted, or if, perhaps you intend to fish a stream where stealth and accuracy are more important than distance?

Great question!

This is where downsizing should be considered. A 7- to 8-and-a-half-foot, 3-weight fly rod might be the perfect implement for small streams that sport a mix of both open water and tight pools and holes that rest under overhanging vegetation. 

The lighter rod is also a better choice in streams where water is particularly clear and where being quiet and stealthy is just as important as being spot-on with your cast. 

One of my favorite cutthroat trout streams in eastern Idaho in the northwestern United States fits this description. 

There are stretches of water where I could easily throw 40 or even 50 feet of line without worrying about my backcast. But there are also secluded runs and pools that flow under cutbanks and fly-grabbing willows and alders. 

For this reason, I almost always downsize to a shorter, lighter rod — my 7-foot, 6-inch, 3-weight rod helps me ease my fly into tight spots with little disturbance, and I can confidently throw enough line to get the job done in more open conditions. 

Limitations? It’s not a great streamer rod, and its short stature makes nymphing a bit more challenging. 

But it’s perhaps the ideal dry-fly rod that delivers flies on target without having to spend an inordinate amount of time chasing flies up trees or trying to unwind the leader and tippet from overhanging branches. 

What constitutes an ultra-light fly rod?

Man standing in the ankle-deep water holding a rod in the woods.
An ultra-light fly rod is any fly rod with a weight of 2 or less. They are designed for intimate fishing in small water where accuracy and delicacy are more important than distance and power.

There’s a bit of cult movement afoot when it comes to ultralight fly rods — implements that are rated as 2-weights or even smaller. And, I’ll admit, when I’m in a fly shop, I tend to gravitate to these small, wispy rods, largely because of where I tend to use them. 

I absolutely love remote trout streams that are as beautiful as they are diminutive. And wild, backcountry trout? They’re my absolute favorite, even if they tend to be on the small side.

A 2-weight rod might be considered a very limited tool for fly fishing, but remember, it’s more about where you put the rod to use than it is about what you wish to accomplish with it. 

Ultralight fly rods are built for intimate fishing conditions — creeks and streams you might be able to leap across with a running start, or very tight quarters where accuracy trumps distance at every turn. 

In water like this, a 6- or 7-foot, 1- or 2-weight rod can deliver flies better than a longer, bulkier rod. 

I have both 1- and 2-weight rods in my closet, and they both get plenty of use come summer and fall, when I venture into high-country creeks and streams. 

In a typical meadow stream, the target might be the size of a king-size bed. In these remote mountain brooks, the target shrinks significantly — you might have to accurately cast a fly to a target the size of a basketball

A shorter and more supple fly rod is built for these closed-in environs. And, while the fish might be more willing to eat thanks to an environment where food can be scarce, being accurate is still vital. 

In conditions like this, you may find yourself casting from your knees, or negotiating the ideal “bow-and-arrow” cast into a pool shrouded by overhanging brush. 

And don’t think weights stop at 1 or 2. There are fly rods on the market rated as 0- or even 00-weight rods. These miniscule tools have their place and serve a purpose for anglers who really value small water and the wild fish that call it home. 

Final thoughts

Man fishing in the river with his rod with beautiful mountain and trees.
Choosing between light and ultra-light fly rods should be determined based on where you’ll fish, and what kind of water you’ll be fishing, and not so much based on fish you’ll be after.

There are marked differences between light and ultralight fly rods. The most notable difference is their suitability for certain water types. Think about where you intend to fish, and then match the water type to the proper rod. 

Consider a 9-foot, 4-weight rod if you plan to fish smaller water with more open casting opportunities and the ability to present dry flies, nymphs and streamers. The longer rod allows you to be more diverse in your angling and the traditional length can help you add distance to your cast when needed. 

For more intimate water where dry flies are the name of the game and tighter casting conditions are the norm, not the exception, consider sizing down to a shorter 3-weight rod. 

And, for truly intimate fishing where distance is an outlying factor and accuracy is paramount, you should consider an ultralight fly rod — a 2-weight or lighter implement that’s made for tight quarters and shorter, more accurate casts. 

Yes, trout might be smaller in high-country or remote country streams, and they might be more willing to chase flies. But that doesn’t mean you should chase them with the improper fly rod.  

I’ve found that sizing my rod to the water is a more effective gauge than overthinking the target trout. A light rod can handle larger trout in tight quarters, but a longer, heavier rod can be a hindrance in intimate angling situations.

In other words, think about the angling conditions first, and the size of the trout second when you choose between light and ultra-light fly rods.  

Chris Hunt Avatar


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