The San Juan Worm

By John Berry

Last week, I finally got a chance to wade fish Rim Shoals on low water with my wife, Lori, and my yellow lab, Ellie. I caught a lot of good fish including a twenty inch rainbow on a grasshopper. The biggest fish of the day, a much fatter twenty inch rainbow that put me into the backing before I finally landed it, was caught on a red San Juan worm. It came as no surprise that I landed my biggest trout on this particular fly. Earlier in the month I had guided a client to a twenty six and a half inch brown while he fished with a hot pink San Juan worm. In fact, I have caught a substantial portion of my bigger fish on them. It is a fly that I personally fish every time I am on the river.

The San Juan worm has earned a major spot in my fly boxes. One of its appealing characteristics is its ease of fishing. The most effective way to fish it is to dead drift it under an indicator. If you are fishing a zebra midge, scud or other nymph and you want to try a worm, all you have to do is clip the nymph off and tie the worm on. Make sure you have a perfect drag free drift and set the hook when you detect any take. Fish on! You will notice that fish will hit a worm pretty aggressively. This represents a reliable food source and a big bite.

Our local rivers have aquatic worms. They tend to be small and either red or worm brown. Most of the worms available to trout come from the shore. Whenever it rains, worms are flushed out of the ground and washed into the river. Just after a rain is the best time to fish San Juan worms. The trout have seen plenty of them and they are keying in on these large tasty morsels. These worms are a bit larger and generally brown. We get the same effect when we have a period of high generation after the river has been down for a while.

When I first started tying them, I used long shank streamer hooks. Then, when I was on vacation in Yellowstone a few years ago, I saw some San Juan worms tied on an English bait hook (Mustad 39160) at a fly shop. I was drawn to the heavy wire and wide gap. I began tying all of my worms on that hook. The down side was the very large barb on this hook and with its wide gap it tends to grab the bottom. Recently, I began tying them on size fourteen scud hooks (Tiemco 2487BL) and I have not noticed any difference on hook ups. This hook is factory barbless and penetrates well. For high water, I tie them on 1/32 ounce jig heads. These hooks offer a couple of distinct advantages. Their extra weight helps get the fly to the bottom and they naturally drift with the hook point up rendering them weedless.

The weak point on San Juan worms is the thread lashing the chenille to the hook. It can easily be cut by a trout’s teeth or a pair of clumsily handled forceps. You can significantly increase the life of your worms by carefully removing them with just your fingers. You can increase the durability of your worms by using a heavier thread (6/0) and by tying a whip finish at both ends of the fly, at the eye and at the bend of the hook. I experimented with tying them with Kevlar thread but found it difficult to work with.

For years, I only tied worms in red and worm brown. They worked well and they are still my favorite colors for low water. A couple of years ago I began experimenting with bright colors for high water. I have found cerise and fluorescent hot pink to be my most productive colors. San Juan worms in these two colors have become my got to flies for high water. I have also found them to be productive for moderate flows.

The preferred material is ultra chenille, which is synthetic chenille. The advantage of this material is that you can singe the tips of the worm with a cigarette lighter and create a tapered body which is more realistic looking. Great care must be taken because this material, like many others, is flammable. You do not want a uncontrolled blaze going through your fly tying materials. Ultra chenille comes in two sizes, regular and micro. The most useful is regular, which I use for most of my San Juan worms. I also tie micro worms with the micro chenille. The micro worms are very effective in certain situations, particularly on the Norfork River.

Another material for San Juan worms is pearl cord braid. This is a synthetic cord that has an outer braid made of shiny pearlescent fibers. This material has sheen to it and it comes in a variety of colors. Some local anglers swear by it but I have had mixed results.

A number of anglers tie their worms with chamois. This is a natural leather product that has good movement in the water. It is very inexpensive. They just buy a chamois, like you would use to dry your car, and cut it into thin strips and then lash a strip to a hook to create a fly. I have had a bit of luck with chamois worms and carry a few in my fly box.

The San Juan worm is easy to tie and it catches fish. If you haven’t tried them, you should. If you already use them, you know what I am talking about.

John Berry
(870) 435-2169
berrybrothers@infodash.com
www.berrybrothersguides.com