Skip to Main Content

Drifting in the Stream: A Guide to Fly Fishing for Trout

Fly used in fly fishing

Photo by John Mullican, DNR’s Fishing and Boating Services

The mystique of fly fishing often intimidates anglers, preventing them from trying this fun and productive method of fishing. Sure, expert proficiency with multiple casting and fishing techniques can take years to hone, but is not necessary to catch fish to enjoy the sport.

Fly fishing is most popular among stream trout anglers as the method was developed to present imitations of the aquatic and terrestrial insects that make up the bulk of a trout’s diet. Depending on the geographic location, water quality, and habitat of the stream, a variety of aquatic insects will be present. Most common will be stoneflies, mayflies, and caddisflies. Though the life cycles may vary, all include a one- to two-year aquatic stage and a brief adult stage where mating occurs and eggs are deposited in the stream, repeating the cycle.

Flies that imitate the aquatic stage are called “nymphs” and the adults are imitated with “dry flies” because this stage floats on the surface. Trout observed flashing on the bottom or in the water column are taking nymphs in the drift. Trout splashing or slurping at the surface are taking the adults or nymphs as they are emerging into adults at the surface, a time at which they are particularly vulnerable. A strong hatch of insects with many surface-feeding trout to cast to is what fly fishing dreams are made of, but in reality, trout are feeding on drifting nymphs most of the time, year round, and this is a good place to start.

Photo of rock with nymphs

Overturned rock with a variety of natural nymphs to imitate. Photo by John Mullican.

A degree in entomology is not a prerequisite for catching trout on flies. Turn over a few rocks in the riffles of the stream and what do you see? Most likely, there will be a variety of aquatic nymphs in shades of tan, olive, brown, and black wriggling about. A suggestive nymph pattern of a similar size and color will catch fish. Nymph patterns that are suggestive of a variety of insects will be particularly effective over a range of conditions. Hares Ear and Pheasant Tail nymphs in sizes 12 – 18 are standby patterns that imitate a variety of mayfly nymphs.

Similarly, a Walt’s Worm is a very simple pattern that accurately suggests a caddis larva. Because nymphs mimic the aquatic stage of insects, they are usually weighted with fine lead wire or a tungsten bead. A local fly shop can suggest effective patterns and hatch charts can be found on the internet for just about every popular trout fishery. Hatch charts indicate what insects to look for seasonally and usually list appropriate fly patterns.

A basic selection of cream, sulphur orange, olive, and grey dry flies in sizes 12 – 18 will cover most options to mimic the adult stage of aquatic insects. Elk Hair Caddis and the Adams are two dry fly patterns all fly anglers should carry. A powder or paste floatant is added to the leader and fly to help them stay buoyant and on the surface. Many anglers use a “dry-dropper” rig that consists of a nymph on a short section of tippet (monofilament/fluorocarbon line) tied to the bend of the dry fly. This allows the angler to present both the nymph and adult stages of aquatic insects at the same time; the dry fly also acts as an indicator signaling when a trout takes the nymph.

With conventional fishing tackle, the weight of the lure and flex of the rod are used to propel the lure during the cast, pulling the line from the reel. Flies, which lack sufficient weight for conventional casting, are propelled by the flex of the rod and the weight of the line. A tapered leader is used to transition from the thick fly line down to thin monofilament or fluorocarbon to tie to the fly. Leader lengths and breaking strength vary with water conditions and the size of the flies used. Fly anglers carry spools of tippet material of varying sizes to add to the leader to meet conditions so that the entire leader doesn’t have to be replaced each time a fly change is made. There are many resources available online to learn the basic casting stroke.

Photo of flies used in fishing

Variations of Elk Hair Caddis and Adams dry fly. Photo by John Mullican.


It is important to match the fly rod with the appropriate weight line for the type of fishing you intend to do; fly rods will have the length of the rod and the recommended line weight inscribed on the rod just above the handle for reference. Line weights of 1, 2, and 3 are generally for small flies and very delicate presentations, line weights of 4, 5, and 6 are considered good “all purpose” sizes suitable for a variety of freshwater species and fly sizes, while weights 7 and up are progressively heavier to handle larger flies used for bass, pike, and muskie. For general river and stream fishing, a double taper or weight-forward floating fly line is ideal. The most versatile rod lengths are 8 to 10 feet.

Regardless of whether nymphs, dry flies, or a combination are used, the goal is to present the flies in such a manner that they drift naturally in the current, as if they aren’t attached to the line. This is one of the most challenging aspects of fly fishing as currents of varying speed and direction will pull on the line and leader causing the fly to drag unnaturally. As cast length increases, so too does the potential for unnatural drag. A section of line and leader that is being pulled downstream faster than the fly can be addressed by using the rod to flip the line back upstream, called mending, before it has a chance to pull the fly. A more effective approach is to make shorter casts, about 30 feet, and use the length of the fly rod to keep most of the line off of the water so it isn’t influenced by the currents.

Fly-fishingMaryland has a lot to offer both experienced and new fly anglers and a number of helpful resources to assist you. Hatchery brown and rainbow trout are stocked at locations throughout the state seasonally. Wild brook, brown, and rainbow trout are available in small mountain streams and tailwaters such as North Branch Potomac River, Savage River, Youghiogheny River, Big Hunting Creek, and the Gunpowder River. Beaver Creek in Washington County offers a unique, and challenging, spring creek experience. An interactive map of Maryland’s trout management areas is available on the trout fishing webpage to help you choose a destination. A map of the five freshwater management regions is available on the Freshwater Fisheries homepage. Clicking on the regions in the map will bring up an overview of the region and staff contact information. Staff are happy to help you have a great Maryland fly fishing experience.

John Mullican is field operations manager for the Maryland Department of Natural Resources Freshwater Fisheries Program. Article appears in Vol. 25, No. 1 of the Maryland Natural Resource magazine.