The Serendipity and $3 Dip, originally known as the $3 Bridge Serendipity are effective patterns to have in your fly box. I posted the following picture on my RiverKeeper Flies Facebook recently to share its effectiveness…

Rainbow & $3 Dip |

…and received a comment asking two questions:

  1. What does it imitate?
  2. How do I fish it?

I thought about it for a few seconds and said “there’s the topic for my next blog post”!


The original Serendipity was developed by Ross A. Merigold, a famous guide from California who loved and fished the Madison River in Montana. In fact, there is a bronze plaque on a boulder just above Raynold’s Pass Bridge identifying the Ross Merigold Hole.

Ross Merigold Sign on Madison River at Reynolds Pass Bridge |

Ross was the inventor of the RAM Caddis, which imitates a caddis pupa or caddis larva. Word has it someone tried tying the RAM Caddis, didn’t have all the materials and substituted deer hair.

RAM Caddis
RAM Caddis |

Craig Mathews from Blue Ribbon Flies in West Yellowstone, MT describes and ties an original Serendipity in the following video.

I first ran across the original Serendipity in Randall Kaufmann’s Tying Nymphs. I tied many flies from that book in the 1990’s. I’m sure I fished the fly, but don’t recall if I caught fish. Here is one of those flies I tied back then.

Serendipity |

What does it imitate?

It depends. Gotta love that answer!

Most of the time, a fly pattern is developed to imitate a specific insect or stage of insect.

Other times, a fly pattern seems to cover a wide spectrum of insects. It appears the Serendipity falls into this category.

The original Serendipity was tied with brown Zelon, twisted into a rope and wound forward. As Craig said in the video, fish may think it’s a caddis, mayfly nymph, or midge. That narrows it down, doesn’t it?

In Craig’s book Fly Patterns of Yellowstone, Volume Two, he provides a history of the Serendipity and the variations his guides tied. He credits Nick Nicklas, a well known Blue Ribbon Flies guide, as tying it with brown thread to create a slimmer profile.

The profile of a $3 Dip is so slim and the color is similar to a Pheasant Tail Nymph, the fly I’d normally use for a mayfly nymph. The thread body of the $3 Dip forces the fly tyer to create a slim profile. I believe that’s the key to it’s fishing success.

$3 Dip

$3 Dip - Gold Bead |

Most of the year, I fish it in a size 16. But in winter, I tie it in a size 18 to imitate a BWO Nymph.

As mentioned above, the Serendipity has many variations developed by Blue Ribbon Flies. Two popular variations are the Guides Serendipity and Crystal Serendipity.

Guides Serendipity
Guides Serendipity - Green Zelon |

Crystal Serendipity

Crystal Serendipity |

How to fish the fly

There are several ways to fish this fly. It depends on where in the water column you’re fishing.

Most of the time, I use a two fly set-up. Tie on a heavier nymph to a 9′ leader with an improved clinch knot. Then attach about 18″ of tippet to the bend of the hook with an improved clinch knot. Lastly, tie on the $3 Dip with another improved clinch knot.

I’ve been using a weighted size 12 Red Copper John and attaching a $3 Dip to it. If I can see fish working towards the bottom of the river, I’ll tie on a size 4 – 6 black stonefly nymph first with the $3 Dip extending off of it. If you can’t see fish working in the water you fish because it’s not clear like the spring creek I fish, experiment with different flies to find the correct depth. The fish will tell you!

I usually use a “high stick” method with no indicator. Keep a tight line as the flies float towards you by raising the rod, slowly stripping line in, or a combination. I’ll try to keep the nymph at the same depth throughout the entire drift.

Another popular method to fish this setup is to attach a strike indicator to the leader and try to get a drag-free drift. When the indicator goes down, set the hook.

If you see fish just under the surface of the water, try a “hopper/dropper” setup. Use any dry fly and attach a tippet of 18″ with the $3 Dip. Just watch the indicator fly…when it moves, set the hook.

Final thoughts 

So I thought perhaps I had it all figured out. The $3 Dip I’ve been fishing and catching with was going to be a BWO or PMD nymph. Yup, that’s what the trout thought it was. I was certain.

Well, I recently went back to the river and used the same setup…a size 12 Red Copper John and size 16 $3 Dip as a dropper. Caught several fish again. One fish was big enough to straighten out the hook somewhat and when I tried to bend it back, I ended up breaking the hook. It was my last $3 Dip (gave the other one to my friend Ron on the river). Looking in my box, I saw the Crystal Serendipity in a size 14. Knowing I already started writing this blog, I thought I’d do some “research”. So I tied it on my tippet and…caught more fish.

There went my theory about the fish taking a size 16 fly as a mayfly nymph. (I thought I’d regale you with an expert theory about what the fish were taking it as.)

I’ve heard it said by many anglers…”oh, to be a fish for a day…then I’d have it all figured out”! I’ve said that more than once.

So what does the Serendipity imitate? I don’t have a clue. I’ll go back to what the experts say. Trout may think it’s a caddis larva or pupa, mayfly nymph, or midge. I think it depends on the time of year and size of bugs hatching. When I don’t know what to use, I always tie on a size 16 $3 Dip.

Give the Serendipity and $3 Dip a try and let me know what you think.

Enjoy…go fish!

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  1. Picture is of my largest trout on a fly ! An olive pine squirrel leech. Eastman Lake where Lava Creek enters the lakes

  2. Got to your blog from Max Johnson. Enjoy it. I like fishing The Crooked River. Little Zebra midges and small size 18 and 20 mayfly imitations worked well for me late August and early September. Intend to fish June and July as well as August and September this summer.. Take a trip to Wyoming in early July. Fish the New fork from Town to Airport and the Upper Green from Forest Boundry down about 15 miles. All from drift boat, get to use big dries.. Waterwalker Grey Drakes and Green Drakes (fun to tie) Been tying for 40 hrs. Hope our
    paths cross someday on the Crooked. Spend the summer in the Bend area.

  3. Great post. Its really nice to get the history of a fly and see some variations. I look forward to tying this winter with COF.

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