With the runoff starting to creep up on us, one of our favorite flies to use this time of year is the jigged Olive CDC nymph. It’s a great pattern that can be fished year round with consistent results; however, it does seem to perform best during early spring through late summer. What makes this pattern so effective is the CDC feather—AKA: Cul De Canard. What’s unique about the CDC feather is its ability to trap air bubbles making the fly look like an insect rising to the surface to hatch. Regardless of the feather’s magic, when tied on properly, the individual feather strands dance in the water giving the fly a lot of movement and life making it irresistible to trout.
The Olive CDC is a fly pattern that mimics a lot of natural bugs in the water depending on the time of year it’s used. In early spring when the runoff hasn’t kicked up, we prefer to fish size 14’s as the fly gets down quickly and mimics mayfly nymphs. During the spring and summer we like using sizes 10’s and 12’s as they sink faster in the higher flows but more importantly, resemble green drake nymphs and stoneflies. Once the ice has thawed and we can fish the high country lakes, we’ll tail it behind a small woolly bugger and strip it in. The combination of the slow stripping action and CDC feathers drives lake fish nuts! In this situation, we’re using a smaller size 16, which imitates a baetis nymph.
Olive CDC’s are incredibly versatile and productive, no matter what time of year it is, so for these reasons it’s a staple in our Fly Tins. The combination of heavy tungsten bead and jigged hook causes the fly to ride hook upwards. These hooks cause the least amount of harm to trout and other fish and typically results in an upper lip hook up.
You can fish the Olive CDC any way you want, just be prepared to land some fish as this fly is one that always gets the job done.
How to tie the olive CDC:
Hook: 400BL jigged hook #10-16
Bead: Appropriate size gold slotted bead
Thread: 6/0 UTC olive
Tail: Pheasant tail fibers
Body: Olive Hairline dubbing / Opal mirage tinsel or flashabou
Ribbing: Small copper wire
Thorax: Ostrich hurl
Finish with: Olive CDC feather
Use 400BL jigged hooks from size 10-16 for these with appropriate sized slotted tungsten gold bead.
Tie on 6/0 UTC olive thread to your hook then wrap the entire hook shank all the way to the bend.
Trim 6-8 pheasant tail fibers and attach them at the hook bend. The length of the PT’s should the length of the shank from the bead to hook bend.
Once the PT’s are tied in, trim a few inches of Opal Mirage Tinsel and tie that on to the hook bend. At that same point, tie in a section of brassie size copper wire.
Once affixed, get some Olive Hairline dubbing and create a thin dubbing noddle on your thread. Start dubbing about ¼” in front of the hook bend and begin wrapping the hook towards the bend. You’ll get to the end and then start overlapping the dubbing and forming a tapered body until your roughly 2/3rds of the way down the hook.
At that point take your Opal Tinsel and cover up the top of the dubbed body. Once tied off, wrap the body and tinsel with about 4-5 wraps of the copper wire. Tie off the wire and get 4 nice strands of natural color Ostrich Hurl. Tie the ostrich hurl by the bead and begin wrapping the hurl with thread back towards the point where the dubbing, tinsel and wire were tied in. Once there, begin wrapping the ostrich hurl forward (your thread should be by the bead now) and build a nice collar. It usually takes a good 3-6 wraps depending on the size hook your using.
Once the hurl is tied off, get a nice Olive CDC feather and preen the feathers so they are perpendicular to the feathers Rachis. Tie in the tip of the CDC with about 3 wraps of your thread. Begin wrapping the CDC slowly while preening the feather strands backwards so they form a nice buggy collar. You usually get 1.5 to 2 full wraps around your hook. Once the feather is tied in, whip finish the fly and put some head cement on the thread.
Some of the CDC strands will be longer than the hook and that is fine. You want the CDC’s to reach back to the hook bend. If you want a cleaner looking CDC collar, simply pinch the CDC’s that look long and break them off.