Colorado Fly Fishing Field Guide

Trout Fly Fishing in Colorado
Arkansas River

Colorado Fly Fishing Articles

Fly Fishing Terms Field Guide





Abdomen -posterior section of an insect’s body; located just behind the thorax; typically segmented and large in size relative to other body parts.

Action - a term used to describe the flexing characteristics of a particular rod, generally broken into three categories: fast, medium, and slow. Fast-action rods tend to be stiff and flex in the tip, and can perform well against the wind and with larger flies.  Medium-action rods flex further into the body of the rod, require less force to load, and are typically used in freshwater fishing. Slow-action rods flex nearly to the butt, load at short distances, and are most often used for dry-fly fishing.

Adult - the winged stage of aquatic insects; reproductive stage.

Arbor - the center part of the spool where the backing and fly line are tied and wound.

Attractor - a fly pattern meant to elicit a strike rather than to realistically imitate an insect. Example: a Royal Wulff.

[Return to Top]




Backcast- that portion of any fly cast that extends behind the caster.

Backing - usually braided Dacron, used to take up space on the spool before the fly line is attached.

Baetis -widely distributed genus of mayflies such as Blue Winged Olives (BWO).

Bamboo - oldest rod building material.  Classic fly rod material.

Barb - the backward-facing projection cut into a hook near the point to reduce the chances of hooked fish escaping.

Barbless - barbless hooks are either manufactured without a barb or the barb is squeezed down you’re your hemostats. This feature makes it easier to remove a hook and minimizes the handling and potential damage of a fish you may want to release.

Beadhead - term used to describe a fly tied with a bead near the eye of the hook, simulating a head. Beads can be brass, nickel, tungsten, or ceramic, and typically add weight to the fly in order to help it sink. These will also be variations on standard patterns and will appear frequently in the name of flies such as “Pheasant Tail and Beadhead Pheasant Tail”. Specific types of beads you may see are tungsten, mercury (glass), brass etc.

Belly - middle component of a tapered fly line; located past the tip and front taper, but before the rear taper and running line (see running line, front taper, rear taper, and head).

Biot- a short thick barb from the leading edge of a first-flight feather, typically from a goose or a duck, used to simulate tails, legs, or antennae. Frequently used in the name of the fly.  Example: “Black Biot Midge”.

Blank - the long, slender, tapered cylinder-typically constructed of graphite, fiberglass, or bamboo to which other components are attached during the manufacturing of a fly rod

Blue-Winged Olive (BWO) – See Baetis

Break Off - A break off is when fish snaps the line.  This may be due to an undersized tippet, worn leader or a poorly tied knot.

Breaking Strength - amount of effort required to break a single strand of unknotted monofilament or braided line, usually stated in pounds (example: 6 lb. test).

Butt Section - the thick end of a tapered leader. The section usually attached to the fly line via a loop-to-loop connection or a nail knot.

[Return to Top]




Caddis - one of the three most important aquatic insects imitated by fly fishers. This fly resembles a moth when in flight. At rest the wings are folded in a tent shape down the back.  The most important aquatic state of the caddis is the pupa, which is its emerging stage (also see larva, pupa and emerger).

Callibaetis - widely distributed genus of mayfly that is commonly found in lakes; often called the “Speckled Wing Dun” because of the speckled markings on the leading edge of the adult’s wings.

Cast - This is the motion you make when you collectively 'throw' a fly. There are different types of casting for different fishing applications. (See Back Cast, Overhead Cast, Roll Cast, Double Haul, “S” Cast, Sidearm Cast and Roll Cast).

Casting Arc - The path that the fly rod follows during a complete cast.

Catch and Release - A practice within fly fishing intended as a technique of conservation. Fish should be fought quickly and never allowed to tire to the point of exhaustion, to prevent injury or death. After capture, the fish is unhooked using wet hands ' or no touching if possible ' and forceps and returned to the water as quickly as possible. If necessary, resuscitate by pointing the fish's head upstream into the current and waiting until it swims off under its own power.

CDC - stands for “Cul de Canard” which literally translates to “butt of the duck.” The term is used both to refer to the feathers from the area around the oil gland of a duck and also to the flies tied with these feathers.  Frequently used in the name of the fly.  Example: “CDC Biot Emerger”.

Chenille - a fuzzy rope-like material used for creating the bodies of artificial flies, often utilized in patterns such as the Woolly Buggers and Worms.

Chironomid - scientific name for the family of insects commonly known as midges.  In the pupae stage they typically appear to be small aquatic worms.

Click Drag - a traditional system on many fly reels used to slow down or resist the pulling efforts of a fish.

Clinch Knot - universally used knot for attaching a hook, lure, swivel, or fly to the leader or line. A slight variation results in the improved clinch knot, which is an even stronger knot for the above uses.

Comparadun – a type of no-hackle dry fly. Frequently used in the name of the fly.  Example: “CDC Comparadun BWO”.

Cone Head - Same as a beadhead but the bead is cone shaped (does not refer to a character from Saturday Night Live).

Crystal Flash - the trade name for a synthetic stringy material used in many streamer patterns to add flash and color.

Current Seam (or Seam) - Current seams are formed by the nature of current flow. Usually the middle of a river or stream contains the fastest flow with its edges having slower flows due to friction with the bank and the streambed obstacles. A stream channel's curvature redirects its heaviest flow away from the remainder of the stream creating current seams.

[Return to Top]




Dacron - braided nylon line used for backing.

Dead Drift - a perfect float (the fly is traveling at the same pace as the current).

Delivery - term used to describe the action of casting a fly to a fish or into a promising-looking area of water. See Presentation.

Disc Drag - a mechanical system within a fly reel that creates resistance as the line is pulled off the spool, created by the application of pressure between two or more discs, often made of cork or carbon.

Dorsal Fin - the fin on the back of a fish, often divided into two or three separate sections.

Double Haul - a cast during which the caster quickly pulls and releases the line on both the back cast and the forward cast, used to create greater line speed, enabling the caster to reach farther or cut through wind.

Double Taper - a standard fly line design in which both ends of the line are tapered, while the greater portion or “belly” of the line is level; excellent line for short or moderate length casts, and for roll casting. Available in floating or sinking fly line.

Double Uni-Knot - This knot is used for joining lines of similar or different strengths. Resembles a Blood Knot but easier to tie.

Drag - term used to describe an unnatural motion of the fly caused by the effect of the current on line and leader. Drag is usually detrimental, though at times useful (such as imitating the skating action of the adult caddis).

Drag -Resistance applied to the reel spool to prevent it from turning faster than the line leaving the spool.

Drift - Four types of drifts: Straight upstream, upstream and across, downstream and straight downstream.

Dropper - anything added to the main leader or to the fly at the end of the leader, most often a second fly or a weight.

Dry Fly - any fly fished upon the surface of the water. Frequently used to imitate the adult stage of aquatic insects or female egg layer.

Dry-Fly Floatant - chemical preparation that is applied to a dry fly (before using the fly) to waterproof it.

Dun - first stage in the adult mayfly’s life cycle (as opposed to a Spinner). This is the stage most often imitated by the dry fly.

[Return to Top]




Eddy - a section of water in a stream found on the edge of a current that is less disturbed than the surrounding water, providing a place for fish to hold and for insects to emerge.

Elk Hair - hair from the body of an elk that is used in many fly patterns to supply bulk for a body or to provide added flotation. This will appear frequently in the name of flies such as “Elk Hair Caddis”.

Emerger - pertaining to aquatic insects when the nymph reaches the surface and the adult hatches out.

Eye of the Hook – the circular end of the hook where the tippet is tied.

[Return to Top]




False Cast - standard fly-fishing cast used to lengthen and shorten line, to change direction, and to dry off the fly.

Ferrule - the point where sections of a fly rod are joined and the end of one section fits inside the end of another in an overlapping fashion at the ferrule.

Flashback - any type of nymph fly pattern that has a flashy or reflective material tied in at the wing case. This will appear frequently in the name of flies such as “Flashback Pheasant Tail”.

Floatant - A water-proofing (usually oily) salve or cream that is used to help flies, leaders and fly lines float.

Floating Fly Line - a fly line where the entire line floats.

Fluorocarbon - tippet or leader material with a low refractive index, making it nearly invisible underwater, known for its tensile and knot strength as well as its UV and abrasion resistance. It sinks better than nylon line and used in tippet for nymphing.

Fly - A hand-tied artificial lure imitating natural insects or baitfish to entice fish. Flies incorporate different natural and synthetic materials wound onto or otherwise secured on hooks.

Fly Casting - standard method of presenting a fly to a target using a fly rod and fly line; involves many different casts. See Cast.

Fly Line - key ingredient to fly fishing and made of a tapered plastic coating over a braided Dacron or nylon core. These are generally available in several tapers and in floating, sinking, and sink-tip styles such as double taper, shooting head, weight forward, sink-tip, and floating fly line.

Fly Reel - fishing reel used in fly fishing to hold the fly line.

Fly Rod - a type of fishing rod especially designed to cast a fly line; fly rods differ from other types of rods in that the reel attaches at the butt of the rod with the rod handle always above the reel. Fly rods usually have more line guides than other types of rods of the same length; fly rod lengths vary, with common lengths being between 7 and 9 feet. Materials used in fly rod construction are bamboo, fiberglass, and graphite.

Forceps - hand-operated medical instrument widely used in fly fishing to remove flies from the jaws of a hooked fish feature pliers-like jaws with locking clips so that once they are clamped to the hook, they stay there until released. Also known as hemostats.

Forward Cast - the front portion of the false cast or pick-up and lay-down, and a mirror image of the back cast.

Forward Taper - see weight forward.

Foul Hook - to hook a fish anywhere but in its mouth.

Freestone - type of river or stream with a significant gradient resulting in medium to fast-moving water. Most flows result from snow melt, run-off, or tributaries. Opposite of Tailwater streams.

Front Taper - the transition between the tip and the belly of a fly line.

Fry - the first stage of a fish after hatching from an egg.

[Return to Top]




Graphite - the most popular rod-building material in use today.  Good weight, strength, and flex ratio of any rod building material currently available.

Gravel Guards - a standalone neoprene sock or attachment on a wader to pull over the top of wading boots to prevent gravel from collecting inside the boots.

Grip - the handle of a fly rod, generally made of cork rings sanded in several different configurations.

[Return to Top]




Hackle - a feather, usually from the neck area of a chicken; can be any color (dyed or natural); hackle quality, such as the stiffness of the individual fibers and amount of web, determines the type of fly tied with the hackle.

Hatch - a large number of the same species of insects emerging around the same time.

Haul - a pull on the fly line with the non-casting hand to increase line speed and achieve greater distance.

Head - the tip, front taper, belly, and rear taper of a fly line considered together as one section.

Headwaters - An upstream section of the river before the main tributaries join it. This section is typically much smaller in width and flow than the main section of the river.
Hemostat – See Forceps.

Hook - the object upon which the fly is tied.

Hook Keeper - Made of a loop of thin wire built into the shaft of the fly rod near the grip, a keeper safely secures the fly while still attached to the line.

[Return to Top]




Imitative Flies - flies tied to more closely match specific insects (for instance a BWO). Imitative flies are most effective with trout that are keying on specific hatches.

Indicator - floating object placed on the leader or end of the fly line to “indicate” the take of the fly by a fish or to indicate the path of the drift of the fly.

Improved Clinch Knot - One of the most widely used fishing knots used to attach a fishing line to a fly.

[Return to Top]




Knotless Tapered Leader - a fly-fishing leader entirely constructed from a single piece of monofilament.

Knotted Leader - fly-fishing leader constructed by knotting sections of different diameter leader material to each other to make a tapered leader.

[Return to Top]




Larva - the immature, aquatic, growing stage of the caddis and some other insects; many species of caddis larva build a protective covering of fine gravel or debris to protect them in this stage; a bottom-dwelling non-swimming stage of the insect.

Leader - the section of monofilament or fluorocarbon line between the fly line and the fly; usually tapered to deliver the fly softly and away from the fly line.

Lie - The areas in a river where fish are found.  Resting lies are typically out of the main current. Feeding lies will provide a good source of insects and other food. Lies will typically present cover from predators but this isn’t always the case.  (Also See Story)

Line Weight - the weight (measured in grains) of the first 30 feet of a fly line, used as a way to standardize fly lines in matching them to fly rods of differing stiffness. Example: 5 weight line and rod.

Loading the Rod - phrase used to describe the bend put in the rod by the weight of the line as it travels through the air during the cast.

Loop-to-Loop - quick and easy connection system typically used to attach a fly line to a leader by making a loop at the end of the leader, pulling the fly-line loop through the leader loop, then pulling the entire leader back through the loop attached to the end of the fly line.

[Return to Top]





Matching The Hatch - An attempt by a fly angler to select an artificial fly that imitates the color, size, shape and behavior of natural insects that fish are feeding one. Often when a hatch is happening, fish become very selective and refuse insects that do not match the predominant insects present.

Mayfly – An entomology type that is frequently imitated  and include a nymph stage of the mayfly that lasts approximately one year, an adult stage last one to three days.  Adults have one pair of upright wings that look like sails. Commonly found in cold freshwater environments.

Mending Line - method used after the line is on the water to achieve a drag-free float, typically consisting of a flip, or series of flips, with the rod tip.

Midge - a term properly applied to the small Dipterans that trout feed on. Similar to mosquitoes, midges have two wings that lie in a flat “V” shape over the back when at rest; term sometimes loosely applied. See Chironomid.

Monofilament - a clear, supple nylon filament used in all types of fishing that is available in many breaking strengths.

[Return to Top]



Narrow Loop - term that describes what the fly line should look like as it travels through the air. A narrow loop can best be described as the letter “U” turned on its side.

Nipper – A device, similar to a finger nail clipper, used to cut the tag end of fly line and tippet.

Nymph - immature form of aquatic insects.

Nymphing - fly fishing with nymphs.

[Return to Top]




Open Loop - term used to describe what the fly line looks like as it travels through the air during a poor cast caused by a very wide casting arc.

Overhead Cast - This is the traditional fly rod cast most people associate with fly fishing. It is used for presentation of everything from nymphs and streamers to wet flies and dry flies. The Overhead Cast has five parts: Pause, Pickup, Back Cast, Forward Stroke and Shooting the Line.

[Return to Top]




Parachute - type of dry fly where the hackle is wound horizontally around the base of the wing like a parachute instead of vertically around the hook of the fly. This drops the body of the fly down into the surface film of the water. It is usually most effective in medium to slow moving waters.

Pectoral Fins - the pair of fins just behind the head of a fish.

Pelvic Fins - the pair of fins on the lower body of a fish.

Pickup (and Lay Down) - In this part, you lift the fly line off water by moving your hand, wrist, forearm and upper arm in an upward arc. Then bend the elbow and move the wrist, forearm and upper arm in a backward motion rotating at the shoulder. This will pick the line up and start the back cast over your shoulder .

Pool - A segment of a river or stream featuring slower currents and increased depths that helps protect fish from predatory birds and animals. Pools also give fish a rest from swimming against heavier currents.

Presentation - the act of putting the fly on the water and offering it to the fish. The object is to present the fly in a manner similar to the natural insect or food form that you are imitating.

Pupa - the transition stage between the larva and the adult.

[Return to Top]




Reach Cast - a cast used for adding extra slack in the line, or when fishing downstream, in order to provide a more natural float.

Rear Taper - the transition between the belly and the running line sections of a fly line.

Redd - a clearing in the sand or gravel of a riverbed created by breeding trout or salmon for use as a spawning area.

Retrieve - bringing the fly back towards the caster after the cast is made.

Riffle - A quickened flow of water over smaller rocks or gravel, either at the head or tail of a pool. Riffles can be very productive when fished with a two-fly rig, often nymphs.

Rise - the action of a fish as it comes to the surface of the water to feed.

Rod Flex - synonymous with action. The manner in which the rod bends during the cast during the acceleration phase of the cast. Tip-Flex rods bend primarily through the tip section, Mid-Flex rods bend down into the middle section, and Full-Flex rods bend throughout the entire rod during the cast.

Roll Cast - one of the three most basic fly casts; allows a cast to be made without a back cast and is essential for use with sinking lines, to bring the line to the surface so it may be picked up and cast in a normal manner. The roll cast is useful when you lack the open space for a backcast. Instead of making a backcast, build momentum by rolling the line in an rolling motion that replaces the backcast stroke.

Run - A place where the water comes in between a bank and a rock or between two rocks. A run can be fast to slow. If the run has several large rocks along one side, trout can hold against the side of these rocks. The same applies to a bank area.

Running Line - the long, thin part of a fly line that connects to the backing at the reel end.

[Return to Top]




“S” Cast - cast used to put deliberate and controlled slack into a cast in order to get a drag free float.  Same purpose as mending line (see drag, dead drift, and mending line).

Scud - a small freshwater crustacean similar in appearance to shrimp. Found in large numbers in tailwater streams.

Seam Water - The area where two current flows comes together (one slower, one faster), ideal for holding trout. Fish will hang out in the slower flow and dart out into the faster flow to feed. Look for seam water where an island splits the main current or a couple of large rocks may divert part of the main flow.

Setting the Hook - the act of pulling the hook into the flesh of the fish’s mouth.

Shank - The long straight part of the hook between the eye and the bend.

Shooting Taper or Shooting Head - a short, single-tapered fly line, 30-40 feet long; shooting heads are designed for longest casts with minimum effort.

Sidearm Cast - Sidearm casting is useful for fishing in windy conditions and for casting under overhanging vegetation. The sidearm cast uses the same casting strokes and principals as the overhead cast; these strokes are just completed on a tilted side plane.

Sinking Fly Line - a fly line in which the entire length of the line sinks beneath the surface of the water. Often used for streamer rigs.

Spawn - the reproductive behavior of fish.

Spinner - the egg-laying stage of the mayfly.

Spool - the part of the fly reel that revolves and which holds the backing and the fly line.

Standing Line - the part of the line that is joined to another piece of line when tying the tag ends together. Two standing lines are joined by tying their tag ends into a knot.

Stonefly – Key aquatic insect. Nymph lives for one to three years, depending on species and hatch by crawling to the shoreline and emerging above the surface.

Story - A lie that a fishermen tells about the fish (s)he caught.

Streamer - fly tied to imitate the various species of baitfish upon which game fish feed.

Strike - The attempt a fish makes to eat a fly, successfully or not.

Strike Indicator – A floating object placed on the leader or end of the fly line to "indicate" the take of the fly by a fish or to indicate the path of the drift of the fly.

Stripping Line - Retrieving the line by pulling it in through your fingers.

Surgeon’s Knot - excellent knot used to tie two lengths of monofilament together.

[Return to Top]




Tag (Tag End) - the end of the line that is used to tie a knot.

Tailwater - the downstream section of a river or stream found below a large man-made dam.

Tapered Leader - a leader made of monofilament and used for fly fishing.  The back or butt section of the leader is of a diameter nearly as large as the fly line, then becomes progressively smaller in diameter as you approach the tip end.

Terrestrial - land-based insects, such as ants or grasshoppers, that are often food for fish.

Thorax - normally associated with nymphs, however can be a part of the fly, usually the area behind the head, mainly constructed with dubbing.

Tip Section - the top section of a fly rod, smallest in diameter and furthest from the rod grip.

Tippet - the end section of a tapered leader; the smallest diameter section of a tapered leader; the fly is tied onto the tippet.

Truth - See Story.

Turn Over - words that describe how the fly line and leader straighten out at the completion of the cast.

[Return to Top]




Undercurrent - The flow or current of water, below another current or beneath a surface.

Unloading the Rod -  Transferring the casting energy from the rod back into the fly line.

Uni-Knot – See Double Uni-Knot

[Return to Top]




Vest - a fly fisher’s wearable tackle box.

[Return to Top]




Wader Belt - An adjustable belt cinched near the top of chest waders to keep out water, particularly recommended as a precaution in the event of a fall to prevent the waders from filling with water.

Waders - high topped water proof  pants or overalls. There are two main types used in fishing: boot foot and stocking foot. Boot foot have boots built in and stocking foot requires the use of a pair of wading shoes.

Wading Boots - These are boots built specifically to be worn over stocking foot waders. Their soles are made of either felt or rubber.

Weight Forward - an easy casting fly line because it carries most of its weight in the forward section of the line.

Wet Fly - any fly fished below the surface of the water. Nymphs and streamers are wet flies.

Wet Fly - a traditional style of fly tied with soft, swept back hackle, and a backward sweeping wing.

Wind Knot - an overhand knot put in the leader by poor casting, greatly reducing the breaking strength of the leader. They need to be cut out and tied with a knot such as a double uni-knot.

[Return to Top]




X – a measurement used to designate diameter of leader and tippet material used in conjunction with a numeral, as in 4X.  To determine the actual diameter of 4X or any “X” number, subtract the numeral from the number 11 (eleven); the result is the diameter in thousandths of an inch. Example: the diameter of 4X material is .007. Practical usage 3X is thicker and stronger while 7X is lighter and harder for fish to see.

[Return to Top]




Zinger - A retractable device used to hang necessary items off your fly vest ' such as nippers ' to keep them out of the way when not in use.

[Return to Top]



©2014 VFB Solutions

Colorado Trout Flies