Tying the 'Guide Approved' Classic San Juan Worm

Sure - the San Juan Worm isn’t winning any beauty contests. But after years of guiding in Montana, I’ve learned to live by a simple rule: in the worm we trust. My personal guide-record freestone brown trout was landed on this exact pattern.

One of my favorite times of year to guide in western Montana is during runoff. High flows and colored water mean big stoneflies, fishing tight to the willows, and yes — worms. Trying to slow the boat while clients chuck size 4 dries with short droppers under them is pure controlled chaos in the best way, and there’s nothing quite like it.

If you’re filling boxes ahead of spring — or you’re an absolute beginner — this pattern is for you. If I put this worm on a client’s rig anytime in June, we were guaranteed to find a fish.

Why I Fish It

The San Juan Worm shines when fish are keyed in on simple, high-protein meals — especially after runoff or in off-color water. It sinks quickly, shows up well, and doesn’t require much convincing. Fish see into the UV spectrum, with red appearing more brown underwater — just like an aquatic earthworm — and that hot bead acts as a trigger at the collar.

Fish either eat it… or they don’t hesitate for long.

It’s also one of my go-to recommendations for newer anglers or anyone who just wants to fish with confidence.

Why I Tie It (a Lot)

This version is built for efficiency. With only a few materials and minimal steps, you can tie a dozen in no time. That makes it perfect for:

• Stocking up before spring runoff

• Filling guide boxes

• Last-minute trip prep

• Teaching beginners to tie something that actually work

Materials List

Everything you need to tie this guide-approved San Juan Worm:

• Ultra Chenille
  https://redsflyfishing.com/collections/chenille/products/ultra-chenille?variant=44973455048903
• UTC 140 Thread
  https://redsflyfishing.com/collections/thread-wire/products/utc-thread-copy?variant=45051746320583
• 3.8mm Tungsten Bead (Hot Orange)
  https://redsflyfishing.com/collections/beads-cones-eyes-heads/products/umpquas-tungsten-beads?variant=44991193350343
• TMC 2457 Hook – Size 8
  https://redsflyfishing.com/products/tiemco-nymph-fly-hooks-caddis-pupa-shrimp-tmc2457-25pk?variant=44991094751431

(This exceptional worm eating, freestone brown was landed by my client, Robert, in the spring of 2019).