June 24, 2020
By Tom Larimer
This article was originally titled "Stonefly Gluttony: Oregon's Deschutes River Resides". It appeared in the June-July 2020 issue of Fly Fisherman.
Gluttony is defined as “habitual greed or excess in eating.” With synonyms like overeating, binge eating, and piggishness, gluttony perfectly describes Deschutes River rainbows during the spring stonefly orgy. From late April through the middle of June, the “Lower D” pumps out epic hatches of giant Salmonflies, Golden Stones, and Yellow Sallies. During this time, the hard-fighting redsides of this iconic Western river pack on the pounds. For fly fishers, it’s one of best times to chase trout in the 100 miles of canyon water downstream of Pelton Dam.
Any stonefly hatch, regardless of the river, has a tendency to inflate angler expectations. Although this incredible emergence of insects can yield the best dry-fly fishing of the season, it can also be humbling. The secret to stonefly success lies in building a plan of attack based around the life cycles of the bugs. While this article focuses on the lessons I learned during my years of guiding on this high-desert river in central Oregon, most of what follows can be applied to any trout river with a rocky substrate and steep gradient.
The Stonefly Family
Stoneflies require cool, clean, oxygenated water to thrive, and the giant Salmonfly from the Pteronarcyidae family (Pteronarcys species) is no exception. These flying fortresses are the first stoneflies to show themselves each season. The emergence typically happens in the Maupin area (river mile 52) the last week of April or first week of May from evening through early morning. During these low-light hours, the bugs crawl onto boulders and vegetation near the river’s edge. Once their nymphal shucks split and the adult insects emerge, they rest for a couple of days before they mate. After copulating, the females oviposit their eggs on the water’s surface in the afternoon or evening. Due to their preference for silt-free water, most Salmonflies are upstream of the glacially influenced White River, a tributary that joins the Deschutes around river mile 45.
Members of the Perlidae family (Hesperoperla species), Golden Stoneflies begin to emerge during the Salmonfly hatch, typically three to five days after the first Pteronarcys show up. Most years, the first Goldens emerge in the first week of May, though they can pop earlier in warm years. Unlike Salmonflies, the nymph migration occurs mostly in the late afternoon and evening.
The Golden emergence on the Deschutes is the most important stonefly for fly fishers because there are many more of them than there are Salmonflies. By nature, trout focus their efforts on the most available food sources, and Golden Stonefly patterns usually outfish Salmonfly patterns when both species are present. Goldens also populate more miles of the river. Like the Pteronarcys the largest population is upstream of the White River, however, the lower 40 miles also provides some excellent Golden Stone habitat in areas with heavy currents and big rocks.
The smallest and most overlooked stonefly on the Deschutes is the Yellow Sally (Cultus species). These fun-size trout snacks typically start showing up in the lower river on the heels of the Golden Stonefly hatch—around the third week of May—and can last through June. Unlike Salmonflies and Golden Stones, Sallies emerge through the day. Many fly fishers miss this hatch altogether because they are so focused on the big bugs they never think to look for a size 14 stonefly. When a Yellow Sally falls into the water it has an extremely low profile and is difficult to see, so you have to look for them. The trout have no problems locating these delicate little morsels.
When planning to find stoneflies, it’s important to realize the first bugs show up low in the system, and the hatches gradually migrate upstream. Consequently, there can be great fishing in the Maupin area during the first week of May, while the upper river near Warm Springs won’t see any insects until four or six days later. Weather also plays an important role. The ideal scenario is stable, warm weather, the hotter the better. It usually takes a couple of 80-degree days to really get things going. Although central Oregon is known for sunshine, spring storms can push the hatch back by a week or two. If a cold front comes through during the hatch it can radically slow down mating. Although this can make for some tough dry-fly days, it does have a tendency to spread the emergence out and make the hatch last longer.
During the month of April, stonefly nymphs become active, and their migration toward the shallows coincides nicely with the rainbow trout coming off the spawn. Nymphs swept into the current provide easy nourishment for hungry post-spawn fish.
During this period, it’s imperative to have a deep-water and shallow-water game plan. During midday when the sun is high, a 10-foot indicator setup fished through deeper runs and pockets is standard operating procedure. A wide variety of stonefly nymph patterns work well, though it’s hard to beat a Pat’s Rubber Legs in peacock, coffee, and golden color schemes. When deep-water nymphing, look for well-oxygenated water downstream from riffles, and shoreline breaks ranging from 3 to 5 feet deep. In early to mid-April, when the water temperatures are still in the low to mid-50s, the fish are typically stationed on softer current edges. As the hatch gets closer and the water warms during the second half of the month, the trout transition to faster water. Pay attention to where you’re catching fish—once you find the right current speed you can duplicate this pattern.
In the low-light periods seven to ten days before the hatch—especially during the last few hours of the day—trout nose up into shallow riffles and pocketwater looking for migrating nymphs. At times, you find rainbows on the soft insides of riffles in as little as 12 inches of water. In these positions they are hyperaware of predators, so a slow, stealthy approach is critical. Watch a blue heron hunt and you’ll get the idea.
Not only does your approach need to be in full ninja mode, your rig and flies need to be tailored for stealth as well. A “short leash” nymph rig with a stonefly nymph and a small dropper set a short distance from the indicator (for shallower water) is the best way to target fish hugging the shoreline.
In this kind of shallow water, an unweighted or lightly weighted stonefly pattern is a must. The two patterns I rely on are either a Pat’s Rubber Legs or my own Copper Back Golden Stone. When I designed the Copper Back, I wanted a fly that wouldn’t spook fish when it landed, or constantly snag the bottom. At the time of conception (16 years ago), almost every commercially available stonefly was a boat anchor and didn’t perform adequately in skinny water. I also wanted a fly that drifted in the same attitude as a struggling stone in the current desperately trying to find something to cling onto. By design, the Copper Back drifts ass down with its legs extended, a trait that’s critical for fooling large, educated fish.
After the first stoneflies begin to emerge, it takes a day or two before the redsides start keying in to dry flies. During this short recognition period, nymphing tactics continue to produce but it pays to prospect with a dry/dropper, particularly in riffles and pockets during the afternoons and evenings. A jigged Rubber Legs dropped 24 to 30 inches below a golden Chubby Chernobyl can be deadly. Once the fish start zeroing in on the adult insects, some of the best dry-fly fishing of the season follows. This typically happens a couple of days after emergence when the females begin their egg-laying flights in the afternoons and evenings. The fatal dance of fluttering stones dropping to the water to oviposit their eggs rings the dinner bell for hungry trout.
The best surface pattern in my box is one a client nicknamed The Secret Stone. The magic of this fly is that it sits low in the surface, yet it is exceptionally buoyant. Unlike some other foam patterns, it lands upright on every cast and doesn’t twist your leader when casting. Best of all, the trout eat the hell out of it.
During the hatch, the riffles and pockets that produced in the pre-hatch period continue to produce. However, by this time the water warms into the 60s, and the fish often transition to what my mentor and longtime river guide John Hazel refers to as “deep bank water.” Look for micro eddies and pockets of soft water next to heavy water on outside bends of the river. The most productive lies have large structure, lots of foam, and are close to deep water. Riprap banks, dense tree lines, back eddies, and deeper grassy banks are all fish-holding locations.
When the fish are looking up, the most effective approach is an upstream dry-fly presentation. Short, accurate reach casts and perfect drifts are vital. The most common mistake I see on the Deschutes or any big canyon-type water is casting too far. Typically, a long cast is no farther than 20 feet of line out the rod tip. As a general rule, more complex water requires shorter casts. Deschutes rainbows don’t take kindly to poor presentations. One sloppy cast or a fly dragging through a spot puts trout down—especially larger fish. This type of water requires patience and timing to get the right drift.
When I was a guide, I always made my clients watch the river for a few minutes before fishing deep bank water. I wanted them to see that the river has a rhythm. In this type of water, understanding the cadence of the river’s flow often dictates success. At times, the river surges and creates massive upwells. Any presentation with a dry would instantly drag in the washing machine effect of the current. However, if you wait for the surge to subside, the current evens out and presents momentary windows of opportunity.
The old saying “the foam is home” holds true on the Deschutes. Foam is the gravy train, and the trout always position themselves under it. The time to make the cast is when the foam line straightens out just after a surge. Mastering this surgical approach is fundamental for effective dry-fly presentations with the big bugs.
While there are two or three days every stonefly season where the dry-fly fishing is a full-throttle all-day event, most days the best surface fishing is in afternoon pockets of shade, or during the low-light evening hours. Some days the fish get on drys right off the bat, while other days they may not respond to surface flies until 4 P.M. How do you decide what technique to use?
A dirty little trick I devised when I was guiding was to use a strike indicator tied to look like a Golden Stone. I started each morning with a nymph rig, prospecting riffles, pockets, and deep bank water. When the fish started hitting the indicator, I knew it was time to switch to a dry. It’s a deadly tactic that keeps you fishing the most effective technique throughout the day.
At some point during the hatch—typically eight to twelve days after the first bugs emerge—most of the mature nymphs have already made their way to the bank. Consequently, using larger stonefly nymphs becomes considerably less effective. However, this is also the time when the Salmonflies and Goldens that emerged in the first week of the hatch begin to die off. Fishing a drowned adult stonefly can be extremely effective, especially in the mornings. I suspend Larimer’s Spent Stone under an indicator or as a dropper below a dry.
The insane dry-fly fishing typically lasts 14 to 20 days after the emergence begins. While fly fishers should target the same successful spots they fished during the emergence period, the biggest change is fly selection. Early in the hatch the fish are unpressured and willing to eat a wide range of stonefly drys. However, the fish get pickier as the hatch progresses, especially in heavily fished spots. It’s not uncommon to see refusals—trout rush to the surface to intercept the offering and at the last second veer off. You’ll also see them bump the fly with their noses, as if they were testing it to see if it is real.
A few minor adjustments can make a massive difference in the rise-to-hooked ratio. Many popular commercial fly patterns float on top of the surface, while a real stonefly abdomen rests in or under the surface. As a result, low-riding patterns like Larimer’s Golden Stone and the classic Norm Woods Special produce exceptionally well. It also pays to trim off any hackle on the bottom of your fly to ensure it sits low in the water.
Also try downsizing to a size 10 or 12 Golden dry. While considerably smaller than the real insects, a little fly can get the nod when the fish get funky. This is also the period when Yellow Sallies make their appearance. Fish that refuse a Golden Stone late in the hatch will often confidently sip a Larimer’s Yellow Sally.
Another tool for wary trout is to animate your fly. When adding a little movement, it’s essential that your leader and tippet don’t get sucked under the surface. A short-range tuck cast ensures your fly hits the water before your leader. Keeping your rod high, make small shakes with the rod tip to bring life your bug to life. Try to observe real stoneflies struggling to lift off the surface. They frantically shake their wings for a few seconds, and then pause to conserve energy. Your animations should mimic this behavior. Many days—particularly later in the hatch—this rod shake is the difference between a slow day and a “Holy crap we railed them” day.
While the peak of the hatch is usually the first two or three weeks in May, the trout remember the bugs weeks afterward. It always pays to prospect with a stonefly dry, especially in shade pockets or in the evenings, weeks after the last bugs have hatched.
The Deschutes River stonefly emergence has the potential for some serious memory-making days. However, many fly fishers miss seeing the forest for the trees. Be aware that there’s a smorgasbord of other overlapping bugs. Caddis, Mahoganey Duns, Pale Morning Duns, Pale Evening Duns, Blue-winged Olives, Western Green Drakes, craneflies, and midges are all present in May and June. Sometimes, despite millions of stoneflies crawling in the streamside trees, the trout key on what is most available to them. The most successful anglers build a plan based on the life cycles of stoneflies, but are ready to pivot when the trout go off script.
*Tom Larimer is the national sales manager for fly fishing at G.Loomis. He lives in White Salmon, Washington.