The Starting Lineup – 3 Flies You Must Have for April in Colorado
- brianchilbert
- Apr 21
- 3 min read
Insight from CRO Guide Matt Weldon
April is one of the most exciting months to be on the water here in Colorado. With the warmer-than-usual spring we’ve been experiencing, our local rivers are alive with consistent bug activity and some of the best opportunities of the year to find feeding fish. While blue wing olives and midges are still in the mix, caddis are already making a strong push, and the fish are taking notice.
CRO guide Matt Weldon has been on the front lines this month, and when we asked him to break down his Starting Lineup for April, he didn’t hesitate. If you’ve got these three flies in your box, you’re giving yourself a serious edge.
1. Juan’s Kryptonite Caddis – Size 16
If there’s one fly that screams “April” this year, it’s this one.
With the early and aggressive caddis activity we’re seeing, Juan’s Kryptonite Caddis has been an absolute producer, especially when fish are keyed in on emerging bugs below the surface. This fly does an incredible job imitating that vulnerable stage when caddis are drifting and rising toward the surface.
How to Fish It:
Matt recommends fishing this as your lead fly in a nymph rig. Focus on softer seams, tailouts, and any water where fish can comfortably feed without expending too much energy. A dead drift is key, but don’t be afraid to let it swing slightly at the end of your drift. That little bit of movement can often trigger aggressive eats.
Matt’s Pro Tip:
“If you’re seeing even a few caddis fluttering around, this fly should be on your rig. A lot of people wait until the hatch is going strong, but the fish are usually eating them subsurface well before you ever notice bugs in the air.”
2. Hilbert’s Sexi Top May – Size 20
This fly continues to prove itself as a must-have during blue wing olive activity, and April is prime time.
Even with the strong caddis presence, BWOs are still a major player, especially on those overcast, cooler days. The Sexi Top May is a deadly imitation of emerging mayflies and excels when fish are feeding just below the surface.
How to Fish It:
Fish this as your dropper behind a heavier point fly like the Kryptonite Caddis. It shines in slower runs and riffles where fish are suspended and looking up. Light tippet and a drag-free drift are critical.
Matt’s Pro Tip:
“This fly is all about subtle eats. Set on anything, if your indicator hesitates, twitches, or even just feels different, set the hook. A lot of your bigger fish this time of year will eat this fly very softly.”
3. X Caddis – Size 16
When the hatch really gets going and fish start looking up, the X Caddis is your go-to.
With the warmer temps this spring, we’ve already seen consistent caddis coming off in the afternoons, and this fly is perfect for matching adults on the surface. It’s high-floating, easy to see, and fish absolutely crush it.
How to Fish It:
Target banks, seams, and riffles during the heat of the day, typically late morning into the afternoon. Look for rising fish and make accurate, drag-free presentations. This fly also works great in a dry-dropper setup if fish are feeding both on top and just below.
Matt’s Pro Tip:
“Don’t overthink it. If you see fish rising and caddis in the air, tie this on and go to work. And if you’re not getting eats, it’s usually your drift, not the fly.”
Final Thoughts from Matt
April is all about paying attention to what’s happening in the moment. Between BWOs, midges, and now strong early caddis activity, conditions can change quickly throughout the day.
“Start deep in the morning, and as the day warms up, keep an eye out for rising fish. Be ready to adjust. The guys who are willing to switch flies and techniques as the hatch develops are the ones who have those unforgettable days.”
Let’s Get You on the Water
There’s no better time than right now to experience what Colorado has to offer. With fewer crowds, active fish, and some of the best hatches of the year, April is truly special.
If you’re looking to dial in your approach, learn from experienced guides, and have an unforgettable day on the water, book a trip with Colorado River Outfitters.
📞 Call or text us at 970-236-1937
Our guides are on the water daily and ready to put you on fish. Let’s make it happen.
Comments