Tavis Rogers caught this chunky San Juan rainbow on a white San Juan Worm. The pattern seems to have fallen out of favor in recent years, but it still produces winter fish. Photo by Patrick Meitin

When weather turns cold and snow begins to fly, there's ice-fishing (don't get me started), and then there's the San Juan.

During the winter, with the exception of a very few tailwaters like the Rio Chama, the Rio Grande Gorge and others in southern Colorado, there really isn't much else going in the way of quality trout fishing. The river's fame brings anglers from around the globe for this very reason, providing a trout fix when other waters have closed up shop for the season.

Without doubt, SJ winter fishing on the right day can become the stuff of legend. It can also represent the epitome of frustration, given the wrong timing and certain prevailing conditions. I won't address the good days and perfect conditions, because tough days far outnumber them. And besides, even a child can catch trout when all systems are go.

WEEKEND CROWDS
As a life-long New Mexico resident and regular SJ junkie, I sometimes feel invaded on this river. Being self-employed, I've simply learned to avoid fishing there on weekends.

Unfortunately, most of my long-standing friends don't enjoy this type of arrangement. If I want to fish with them, I must suffer the foolishness of weekends. If it's a nice day (meaning sunshine), you might count 56 anglers within sight of a single run that you work so diligently with fly and strike indicator. Frankly, this isn't exactly what draws me to fly-fishing, and it tends to piss me off, even if I'm catching fish. But I've learned to make the best of it.

Winter mornings here can be brutally cold. This means most fly anglers are a bit reluctant to leap from their beds or abandon cafes to assure an early start. Me? I add an extra layer of fleece, pull on fingerless gloves, and hit the river at first light. I get to watch the undisturbed geese and ducks and normally have a dozen trout landed before the maddening crowds arrive to wade ever so ignorantly through my pod of fish or jump into my spot when a big trout pulls me downstream by a 3-pound leader.

The arrival of the masses signals that it's time for a hike. There are a few pockets on the SJ where additional walking (and wading) away from scattered parking lots is a necessity. Instead of fishing your way to these spots, make a beeline to them, wading over fish if need be. By the time the crowds and their silly grins begin to reach you, it's time for lunch anyway, and you can hand these places over to them. This describes the more remote sections of Upper Flats, Lower Flats and Lunker Alley, plus some side channels in other areas you'll have to explore on your own.

Also count on holiday periods like Christmas, New Year's, and such banal events as the Super Bowl to thin crowds considerably. Also, when snow is cascading and highways turn treacherous, risk your neck and hit the river. The fish don't mind, and you'll likely have the place to yourself. I've had some wonderful days on the river while snow accumulated on my hat.

Unless you enjoy crowds, avoid Texas Hole at all costs. Good Lord, don't people understand there's another 3.5 miles of river to be fished besides this easily accessed, overly developed, well-attended place?

DIRTY WATER
Dirty water can be caused by heavy rain or melting snows, but the most common culprit is Navajo Lake "turning over." The fancy name for this is thermal inversion; dirty water on the lake's surface plunges to the bottom, and clean water rises to the top. The dam's deep-water outlets then release the dirty water, creating poor visibility.

Those minute flies that are very much part of fishing the San Juan become difficult for trout to see and intercept. That's not to say trout won't still nab these size 20 to 24 tidbits. They just won't do it as often as they did in clear water. Instead of catching 25 trout, you might catch five. By the way, I've no suggestions on specific patterns, since these seem to change names with every trip up. Generic creations work as well as those with monikers, and fly-shop employees are happy to point out the week's "hot" pattern for you.

Since the dual rig is also very much part of San Juan du jour, I still attach a tiny thing on a dropper. But while fishing dirty water, this normally includes a sparkle wing to grab attention. The point fly becomes something SJ regulars might turn up their noses up at -- like the dreaded San Juan Worm, big leeches, egg patterns or "glow bugs," and (horrors!) big black Woolly Buggers.