On the fly: Don’t overlook the PMD hatch
August 10, 2012
BASALT – Famous Colorado fly tier and lover of the Fryingpan River, A.K. Best, refers to pale morning dun (PMD) mayflies as the “glamour hatch” of the fly-fishing world.
These beautiful mayflies hatch throughout the summer months on most western rivers and streams including the Fryingpan and Roaring Fork rivers. Anglers fishing along the Fryingpan River in particular will find heavy hatches of PMDs occurring daily from about 11 a.m. to 3 p.m.
Though PMDs receive much less attention and press compared to their larger insect counterparts (i.e. green drakes, salmonflies), they nonetheless account for the vast majority of the trout’s diet on the Fryingpan during the months of August and September. Hatches most often take place during late mornings and early afternoons. Unique to our valley is the fact that our PMD duns (winged adults) are pinkish-tan in color. Elsewhere in the West, these insects are generally yellow or pale olive in color. Local lore says our PMDs take on this unique cast as an adaptation to naturally camouflage themselves, given the high amount of red iron ore that is present on the surrounding hillsides.
Prior to the midday hatches, anglers should focus on nymphing the riffles the runs with appropriate imitations of PMD nymphs and emergers. Some of my favorite patterns for this stage in their life cycle would include red copper johns, pheasant tails and halfback emergers in sizes 16-18. As the hatch progresses and sporadic rising fish are being seen, dry/dropper rigs will fish best. Through the thick of the hatch, fish will focus their attention to the water’s surface where the duns rest to dry their wings prior to taking flight. On overcast days, hatches often last for longer periods of time, creating literal fishing frenzies where seemingly every fish in the river is rising.
I often find that during heavy PMD hatches it is best to pick out a single fish to cast to rather than putting flies through a mass of fish and hoping that one of them will eventually eat your offering. Start with the easy fish that are closest to you as to not spook other fish that are rising within the same given area. Light tippets and downstream drifts make a world of a difference in catching these notoriously picky fish.
Last but not least, evening hours create superb opportunities to find rising fish that feed rhythmically to PMD spinners. This is the final stage in the PMD’s life cycle, when the duns mate and eventually fall dead on the water’s surface. Favorite PMD dry fly patterns include sparkleduns in pink, pink flag duns and cdc parachute spinners in sizes 16-18. Don’t delay, some incredible fishing is taking place!