Warmer spring temperatures bring a welcome change around here. But if you’ve been in Colorado long, you know it won’t be a smooth ride from here to summer. Ever heard of false spring? Second winter? No doubt, there will be snow, sleet, and rain ahead. But keep one thing in mind: those nasty spring days create the perfect conditions for hatches of blue winged olives (BWOs).
These small mayflies thrive on cool, overcast days. From about mid-March through late May, don’t let a light snow or drizzly day keep you off the water. It could be the perfect day to experience a BWO hatch.
What Is a Blue Winged Olive?
When we use the common name, blue winged olive (BWO) or baetis, we are referring to a big group of mayfly species that belong to the baetidae family. For anglers, it isn’t all that important to be able to identify every genus and species in the baetidae family. If you enjoy taking deep dives into entomology, the information is available. However, being able to differentiate between a baetis flavistriga and a baetis bicaudatus is not critical to your ability to catch fish.
Because of their many similarities, many flies designed to imitate mayfly nymphs are generic, “close enough” patterns. And for the sake of application, most baetis species can be imitated with the same fly patterns…
A Few of Our Favorite BWO Patterns
From nymphs, to emergers, to dry flies, here are a few baetis patterns you might consider having at the ready this spring…
Bearded Baetis: developed by Anglers All tying expert and Umpqua signature tyer, Ben Baxter, this is one of our go-to baetis nymphs. Purchase them here or watch the YouTube video to tie your own.
Darth Baetis: this pattern comes from our former fly shop manager and Umpqua signature tyer, Greg Garcia. A sleek baetis nymph that fishes well anywhere. Purchase them here or watch the YouTube video to tie your own.
Micro Matcher: Developed here on the South Platte tailwaters by Umpqua signature tyer, Walter Newman, this is an effective baetis nymph. Purchase them here on the website or check out the YouTube video for a tying tutorial.
Barr’s Emerger: John Barr’s Emerger has been a fly box staple for decades, and for very good reasons. It’s one of the most effective emerger patterns ever tied. Pick them up on the website here, or watch the YouTube video to learn how to tie it.
Smoke Jumper: In one of our latest fly-tying videos. Buy them here, or watch Ben Baxter shows us how to tie the Smoke Jumper, a versatile mayfly emerger pattern. Watch the YouTube video here and learn how to tie this simple, yet effective pattern.
High-Vis Parachute Baetis: For those cloudy days on the water during a BWO hatch, try fishing the High-Vis Parachute Baetis. You can purchase them on the website here or watch the YouTube video to learn how to tie your own.
Fishing a BWO Hatch
Nymphs become active in the morning and again in the evenings. So even when there’s no apparent hatch, baetis patterns like the Bearded Baetis can be effective. As the nymphs move their way down the streambed, fishing imitative patterns with a tight line or even swinging them can be a productive tactic.
On cool, overcast days look for hatches of blue winged olives from late morning through the afternoon. We all love a good dry fly eat. But pay attention to where the trout are keying in. During these periods it’s common for fish to be snacking on emergers before they reach the surface. When that’s the case, look to patterns like Barr’s Emerger or the Smoke Jumper. Try fishing these behind a dry fly in the surface film, or under the surface as part of a nymph rig.
When trout are feeding on emergers, this can also be a great time to swing a soft hackle through the current. Tie on a Pheasant Tail Soft Hackle or a Palm’s Biot Emerger. Make quartering downstream casts and swing the fly through the current just upstream from your target.
A BWO hatch can bring periods of great dry fly fishing. But seeing these little dry fly patterns on the water is a challenge. The flat light and cloudy glare can make it extremely difficult to see a white post on patterns like the Parachute Adams or Parachute BWO. When that’s the case, try fishing the High-Vis Parachute Baetis, or even a dry fly pattern with a dark wing or parachute post. You may find that it’s easier to see in cloudy lighting conditions.
Contact Us With Questions
Have questions or need help getting ready for your next day of spring fishing? Visit us at one of our fly shop locations in Littleton or Denver. Or you can give us a call at 303-794-1104. We’d be happy to help with fly patterns, rigging or anything else you need to get started.
