Fishermen often hear the stories about huge stoneflies and the hatches that happen in Western streams. Many don’t realize that stoneflies are found in waters all across the United States, in many varieties. They prefer to live in streams and rivers that are clean and very well-oxygenated and are considered a good indicator of the quality of the water where they are found.
In the waters they inhabit, whether streams, rivers, or lakes, stoneflies can be found under or on rocks in the water, floating along in the current after losing their grip on a rock, or in the current, using it as a vehicle to move downstream. All these movements happen while the stonefly is in its nymphal stage. Prior to becoming adults, the stoneflies will climb out of the water to find a spot to shed their skins and move into the adult stage, to eventually deposit eggs back into the water. Usually, you’ll just see the husks left behind in their transition to adulthood.
Anglers in the Eastern U.S. will encounter little black, little brown, and early stoneflies. Golden stoneflies, often called golden stones, are found in the East, West, and Midwest, and are popular insect food for trout in their waters. The huge black stonefly, often called the salmon fly is found in Western streams and is the source of the fabled stonefly hatch most fly fishermen dream of finding. These larger stoneflies have a longer nymphal cycle, as long as three years, so they’re almost always present in the streams, in varying sizes.
The Golden Stonefly
The life cycle of the stonefly will run one to three years as a nymph, and a few weeks as an adult, after which they expire and fall back onto the water.
Juvenile stoneflies, nymphs, are great crawlers due to claws on their outer leg sections. They crawl around or on rocks in fast water, searching for food. Sometimes, they break loose and get into the stream, becoming easy targets for hungry trout. For this reason, fishing a subsurface stonefly and can be a great way to hook a trout.
Once the stonefly nymphs become adults and begin to deposit their eggs back in the stream, an opportunity exists for great fishing – the hatch. Stoneflies have two sets of wings that beat independently, so they fly poorly, often crashing into the water, and then get too wet to fly, becoming a yummy meal for trout watching from below. They struggle on the surface, causing a feeding frenzy eagerly taken advantage of by the big trout nearby. Some will land on the water, some will skitter and they all fall spent after depositing their eggs, completing the stonefly life cycle.
Fishing opportunities brought on by stoneflies vary:
- Tumbling along in the current, the nymphs can be taken with subsurface flies under an indicator or using a straight-line nymphing method. Learn more about What is nymphing.
- While stoneflies are emerging, moving through shallow water, trout will respond to stonefly imitations and streamers
- During the adult hatch, the dry fly activity can be some of the best, in open current, foam lines, and eddies, where the spent stoneflies accumulate
Look for trout in shallow areas near undercuts and drop-offs, under fallen trees, and overhanging willows. In runoff conditions, the edges of the stream will be cleaner than the rest of the stream, so you might find trout holding there to pick up the Stonefly meal.
If you are considering trying to catch the salmon fly hatch on one of the rivers in the West, know that there are some downsides:
- The hatch only lasts for one or two days on a specific section of a river, so timing can be very difficult. As the hatch moves upriver, it can happen sporadically, hard to anticipate
- There is also an ‘angler hatch’ that takes place, with so many fly fishermen in the river throwing big dry flies that the fish start getting smart and start being more selective in their takes
- Because the salmon flies are so big, once a big trout fills his tummy, he won’t feed again until his food digests
It’s a good idea to go to the area ahead of the hatch and fish the nymphs that are migrating out of the stream. As they get into the current to swim to the banks, trout turn on to the activity. You could also stay behind after the hatch a day or two, and catch the fish still looking for the big stoneflies. Fishing the salmon fly hatch could be your best shot at a 29-inch hog of a trout. That is a memory you won’t soon forget.
More good news! Because of the size of stoneflies, trout will key in on them when they are not taking other foods from the stream. It may be due to their larger size that makes them irresistible to trout. When fishing a stream and having ‘one of those days’, don’t fail to at least try a stonefly – you might be surprised by the tug on the line.
Rich Stuber is the founder of Big Sky Inflatables home of Water Master rafts. Water Master has been used by anglers and hunters all over the world for over fifteen years, including Dave Whitlock, one of fly fishing’s greatest innovators.