San Juan Worm: Glorified Bait?? Not Hardly

by Jake McGlothlin on April 13, 2009

in Flies


I was in a local fly shop the other day when I overheard a customer going off about San Juan Worms.  “Anyone who fishes those is little more than a glorified bait fisherman!”  I heard the man say.  The clerk looked rather overwhelmed, as if not sure what to say.  I just shook my head.  Some people…

Afterwards, I was discussing the man with a fishing buddy of mine.  Ed is kind of purist, so he could see the guy’s point.  I myself am still at that point in life where if a fly catches fish, I’ll use it, purism be damned. 

The San Juan Worm has been the subject of intense debate among some circles of the fly fishing universe.  Some, like the man in the fly shop, wouldn’t fish a San Juan if it was the last fly in their box.  On the other side of the equation are the folks that fish whatever works. Both sides have their merits, and I would love to reach a point in my fishing life when I could honestly say I won’t fish anything but dry flies.  I have a long way to go though.

The San Juan has been around for decades.  Originally developed down on the San Juan River in New Mexico, the fly has spread to almost every corner of modern fly fishing.  Biologists have learned that almost every body of water harbors some population of aquatic worm.  These worms are usually small, one to three inches long, and make up an important part of a fish’s diet.  On some rivers, these aquatic worms have even been known to mass-migrate around the river.

The fly has become incredibly popular for several reasons.  The first and most obvious is that it works.  On almost any river in America on any week of the year, a San Juan Worm will catch fish.  In fact, right now is an excellent time to be fishing this fly around the state.  Another reason is the fact that it is so easy to tie.  Even a novice tyer can whip up some impressive looking worms in no time.  Due to its ultra simplistic design, the worm is also cheap to mass produce.

dscf0345Last spring, a couple buddies and I went for a long weekend trip over to the Boulder River.  We headed south from Big Timber, and drove for almost 50 miles down a beaten dirt road before we decided to stop and fish.  One of my friends knew of an excellent spot that was hard to find and access.  When we got there, by far and away, the most successful fly was the San Juan Worm.  As you can see from the pictures, not all the fish were huge, but they were big enough.





Another beauty of the San Juan Worm is that fact that it can be tied in a variety of colors.  Red and purple are probably the most popular, but brown, green and orange are also productive.  Adding a bead head or some flashy ribbing is a nice touch to the fly.  As with any pattern, local tyers have developed little tweaks and changes to the original to fit their local waters.

No matter which side of the debate you stand on, you have to admit the San Juan Worm deserves a certain amount of respect.