The history of my association with this fly is available in my 03/11/2014 post, and it evolved into a mainstay in my fly box since the inception of this blog. In many instances it is the only blue winged olive imitation required, although I carry the fly in sizes 18 through 24. The broods of baetis that emerge in the fall tend to be more diminutive than their spring cousins, thus necessitating the size 24’s. Normally I utilize size 20 and 22 during spring hatch matching situations.
During 2017 I encountered several instances when my trusted CDC BWO’s failed to meet my expectations. Two notable examples were 04/19/2017 on the South Platte River in Eleven Mile Canyon and 11/01/2017 on the Eagle River. In an attempt to remedy this weakness in my blue winged olive arsenal, I researched and identified the BWO Klinkhammer style as my secret weapon in difficult baetis hatch conditions. The commonality of the frustrating experiences was wind. I theorized that the wind blew the olives off the water, before adults with upright wings became a triggering feature. The Klinkhammer style featured a dangling abdomen on a curved hook with a small wing post and parachute hackle to represent the emerging wing and legs at an early stage.
On 04/05/2018 I faced my first test of blue winged olive hatch matching options. Overcast skies and dim light prompted a steady emergence of baetis on the South Platte River during the afternoon, and my first response was to knot a CDC BWO to my line. I managed to hook and land a couple trout, but the successes required excessive casting, and abundant refusals and lack of interest by visible fish suggested that the CDC version was not the answer. I shifted gears and attached one of my new Klinkhammer BWO’s to my line, and the rest of the afternoon was spectacular. Sixteen energetic South Platte residents were deceived by the new addition to my fly supply.
On 04/16/2018 I arrived on a quality pool on the Eagle River confident that I was armed with the necessary ingredients to fool trout during blue winged olive hatches that coincided with windy conditions. After all, I possessed CDC BWO’s in a range of sizes, and I supplemented these winners with Klinkhammer BWO’s that proved their worth on the South Platte River on 04/05/2018. The weather was very similar to 04/05/2018 with ongoing overcast skies, and wind that gusted up to sixteen miles per hour.
As anticipated small olive bodied mayflies made an appearance at noon, but my line contained a size 20 Craven soft hackle emerger. I knotted this to my leader thirty minutes earlier in an attempt to imitate small gray midges, that held the attention of the fish in the pool. I applied floatant to the body and wing of the soft hackle and decided to continue fishing it as a dry fly trapped in the surface film. I did not observe adults with upright wings and surmised that emergers and cripples were the preferred food source on a very windy day.
It worked! I landed twenty-one trout on 04/16/2018, and fifteen of them succumbed to the greased soft hackle emerger. In addition five slashed at and ate the Klinkhammer BWO. Despite the discovery of new weapons in my quest for blue winged olive hatch matching, I also experienced several days when the CDC BWO earned its place in my fly box.
With all this background in mind I counted my CDC BWO’s and determined that I needed a handful of new models. I produced four size 22 and four size 20 versions, and I feel confident that I have an adequate array of imitations to dupe greedy fish selectively feeding on some stage of blue winged olives. But then again confidence is a dangerous thing in the fly fishing game.