Why the Green Caddis Hatch Deserves Your Attention
When it comes to the Oregon trout scene, May might be the most abundant month on the calendar. But with the Lower Deschutes salmonfly hatch dominating all the headlines — and for good reason — a few of our other May hatches are treated like second-class citizens. In reality, they are anything but.
One of my personal favorites is the Green Caddis hatch that descends upon the upper Willamette Valley as May temperatures regularly climb into the 70s. Unlike mayflies, these big caddis don't mind a warm, sunny spring day. And due to their ample size and behavior on the water, they regularly convince trout to behave foolishly — much like the bigger stoneflies hatching east of the Cascades this time of year.
Green Caddis are larger bugs, typically fished in a size 10 or 12. Green Caddis nymphs are present all season, and a significant part of the trout diet across Oregon, but the primary appeal of fishing them during May is the ability to throw a "bounce" rig — fun, active fishing that elicits highly visual, explosive takes from the fish.
How to Rig a Bounce Rig for Caddis
The bounce rig sounds a bit complex at first, but it is quite simple in theory. Caddis tend to bounce up and down on the water as they lay their eggs. Egg layers are a better source of protein and are the primary target for fish. When they see that bouncing motion, they're interested.
You can replicate this bounce effect by skating your fly at the end of a drift, but it doesn't quite mimic the motion as accurately as one would like. You'll still get fish, but you're limiting the most impactful part of your presentation to the very end of your drift. A bounce rig features a dropper nymph that acts as a counterweight, allowing you to pick up and drop your fly as it swings below you — creating the true impression of a bouncing caddis fly.
This rig can be a bit heavy, so it is best fished with a five-weight or a sturdy, fast-action four-weight. Use a matching reel and weight-forward floating line. Affix a nine-foot 4x tapered leader to your line, then tie on 12–18 inches of 4x or 5x tippet using a double surgeon's knot. Leave your downward-facing tag ends intact and clip off the remaining tag end. You should be left with two tippet tags, one 8–12 inches above the other.
Affix your Green Caddis dry fly of choice — the bushier the better — to the top tag. Below, tie on a weighted, bead head Green Caddis nymph or soft hackle emerger. Sparingly apply floatant to your top fly; carrying a bit of water will help your dry smack back down on the surface film, making it appear vulnerable to the fish.
Presenting the Bounce Rig
Using a relatively short, fixed amount of line, cast across and downstream at 45 degrees — as if you're swinging soft hackles or streamers. Keep your rod tip high and your line off the water so that you have a direct connection from the tip of your rod to your top fly. Manipulate the tip of your rod to bounce the fly up and down on the water under tension. You will get takes on both the dry and your anchor fly, and you'll be able to see both. Be gentle with your hooksets; remember, you're fishing with a tight line, and this hatch brings some large trout to the surface.
If you're in a hurry, you can simply drop your nymph or soft hackle directly off the bend of your dry fly, and you'll still pick up plenty of fish. However, your bouncing motion won't be quite as effortless or natural if your anchor fly is pulling directly on your dry.
Where to Fish the Green Caddis Hatch in the Willamette Valley
Green Caddis are most prevalently found on the McKenzie and Middle Fork Willamette rivers. The McKenzie is best fished as a guided expedition from a drift boat — an excellent way to fish this presentation for hours without breaking a sweat. The Middle Fork Willamette offers better opportunities for bank anglers. Look for riffles and drop-offs.